All questions of February Week 4 for UPSC CSE Exam

Explanation:

Scenario:
- The man has 20 black socks and 20 brown socks in a drawer.
- He needs to take out socks in the dark.

To ensure a matching pair, the man must take out at least 3 socks:
- The worst-case scenario for the man would be if he first picks out 2 socks of different colors.
- In this case, the next sock he picks will definitely match one of the socks he already has.
- Therefore, he needs to take out 3 socks to be sure that he has a matching pair.

Therefore, the correct answer is option A) 3.

The correct answer is d) Neither of them.

Explanation:

The given matches between colors and agricultural productions are incorrect. Here are the correct matches:

1. Silver - Cotton Production
2. Yellow - Corn Production
3. White - Milk Production or Poultry Production

Therefore, none of the given options are correctly matched.

Overview of Big Bang Nucleosynthesis
The Big Bang theory explains the formation of the universe and the primary elements produced in its early moments, known as Big Bang nucleosynthesis. This process occurred within the first few minutes after the Big Bang when the universe was hot and dense.
Production of Light Elements
During this initial phase, the extreme temperatures and pressures facilitated nuclear reactions, leading to the formation of the lightest elements. The predominant atoms produced were:

• Hydrogen: Approximately 75% of the universe's baryonic mass is composed of hydrogen. Protons were formed from quarks, and these protons became the basic building blocks of hydrogen.
• Helium: Roughly 25% of the mass was converted into helium, primarily in the form of helium-4 nuclei, as nuclear fusion occurred among protons and neutrons.
• Trace Elements: Minor amounts of lithium and beryllium were formed, but the quantities were significantly less than hydrogen and helium.

Why Hydrogen Dominates
The dominance of hydrogen is due to several factors:

• Simple Structure: Hydrogen, being the simplest element, requires the least energy to form. The fusion process favored its production over heavier elements.
• Stability: Hydrogen nuclei (protons) are stable and do not undergo further fusion under the conditions present at the time, allowing them to remain abundant.

Conclusion
In summary, while helium was also produced in significant quantities, the overwhelming majority of atoms formed during the Big Bang were hydrogen. This abundance laid the foundation for later star formation and the synthesis of heavier elements in stellar processes.

Given information:
- A is 3 years older than B.
- A is 3 years younger than C.
- B and D are twins.

To find: How many years older is C to D?

Let's analyze the given information step by step:

1. A is 3 years older than B:
- Let's assume B's age as x.
- Therefore, A's age will be x + 3 (as A is 3 years older than B).

2. A is 3 years younger than C:
- Let's assume C's age as y.
- Therefore, A's age will be y - 3 (as A is 3 years younger than C).

3. B and D are twins:
- This means B and D have the same age.
- Let's assume their age as z.

Now, we can equate the ages of A in both cases:
x + 3 = y - 3

Simplifying the equation, we get:
x - y = -6 ...(1)

Since B and D are twins, their ages are the same:
x = z ...(2)

To find the age difference between C and D, we need to find the difference between their ages:
C - D = y - z

Now, let's substitute the value of x from equation (2) into equation (1):
z - y = -6

Rearranging the equation, we get:
y - z = 6

Comparing this equation with C - D = y - z, we can conclude that C is 6 years older than D.

Therefore, the correct answer is option (c) 6.

Introduction:
According to the Constitution of India, the establishment of a new All India Service can be initiated through various means. One of these means is through the Rajya Sabha, which is the upper house of the Parliament of India. This option is considered correct because it aligns with the provisions mentioned in the Constitution.

Explanation:
The All India Services are prestigious civil services of the Government of India, which include the Indian Administrative Service (IAS), Indian Police Service (IPS), and Indian Forest Service (IFS). These services are responsible for maintaining administrative continuity and efficiency throughout the country.

The Constitution of India provides for the establishment of new All India Services under Article 312. According to this article, if Rajya Sabha passes a resolution by a majority of not less than two-thirds of the members present and voting, declaring that it is necessary or expedient in the national interest to establish a new All India Service, then the Parliament may by law provide for the establishment of such service.

Other Options:
Let's analyze the other options given in the question and why they are not correct:

a) More than two-thirds of the States: While the states have a significant role in the establishment of All India Services, the Constitution does not specifically mention that more than two-thirds of the states are required to initiate the establishment of a new service. The provision for initiating the establishment lies with the Rajya Sabha.

b) The Inter-State Council: The Inter-State Council is a constitutional body established to facilitate coordination and cooperation between the states and the center. However, it does not have the power to initiate the establishment of a new All India Service.

c) The Lok Sabha: The Lok Sabha, which is the lower house of the Parliament, does not have the power to initiate the establishment of a new All India Service. The power lies with the Rajya Sabha as per the provisions of the Constitution.

Conclusion:
In conclusion, according to the Constitution of India, the establishment of a new All India Service can be initiated with the initiative taken by the Rajya Sabha. The Rajya Sabha, through a resolution passed by a majority of not less than two-thirds of the members present and voting, can declare the necessity or expediency of establishing a new service. This provision ensures that the establishment of new All India Services is carried out in the national interest and with the consent of the upper house of the Parliament.

Explanation:
Tropical crops are crops that are grown in tropical regions of the world. These regions have a warm and hot climate which is suitable for the growth of such crops. Some examples of tropical crops are:

1. Bananas
2. Pineapples
3. Mangoes
4. Coffee
5. Cocoa
6. Rubber
7. Tea

Therefore, statement 1 is correct. However, statement 2 is incorrect as potato is not a tropical crop. Potatoes are grown in temperate regions of the world such as Europe and North America.

Hence, the correct answer is option B.

Understanding the Incorrect Pairing in Geography and Economics
The correct answer is indeed option 'C' because it inaccurately pairs geography with economics by focusing solely on historical precedence, neglecting the critical spatial factors that geography emphasizes.
Spatial Factors in Economics
- Geography plays a crucial role in economics through the analysis of how location, resources, and environmental conditions affect economic activities.
- Spatial distribution of resources, transportation networks, and market access are essential components that geography examines to understand economic performance.
Historical Context vs. Spatial Context
- While historical context can influence economic policies, it is not the predominant factor in shaping economic activities.
- Geography provides insights into how physical landscapes, climate zones, and demographic distributions impact economic decisions and strategies.
Interdisciplinary Connections
- Geography and economics are inherently interconnected, as geographical analysis offers valuable tools for understanding economic patterns and trends.
- Factors such as trade routes, urban development, and resource allocation are all influenced by geographical considerations, making them vital for economic studies.
Conclusion
In summary, option 'C' incorrectly emphasizes historical precedence over spatial factors, which are fundamental in the relationship between geography and economics. This oversight highlights the importance of considering geographical elements when analyzing economic policies and practices.

Creating a new All-India service is a significant decision that requires a proper constitutional framework. Among the given options, the correct answer is option 'C', which suggests that a resolution under Article 312 of the Constitution can be used to create a new All-India service. Let's explore this answer in detail:

Article 312 of the Indian Constitution:
Article 312 of the Indian Constitution empowers the Rajya Sabha to pass a resolution by a majority of not less than two-thirds of the members present and voting, declaring that it is necessary or expedient in the national interest to create one or more All-India services. This article provides a constitutional provision for the creation of new All-India services, which are crucial for the efficient functioning of the government and administration.

Process of creating a new All-India service under Article 312:
To create a new All-India service under Article 312, the following process needs to be followed:

1. Proposal: The proposal to create a new All-India service must be initiated by the central government, keeping in mind the national interest and the need for such a service.

2. Rajya Sabha Resolution: The central government presents a resolution in the Rajya Sabha, which is the upper house of the Parliament. This resolution must be passed by a majority of not less than two-thirds of the members present and voting.

3. Lok Sabha Approval: After the resolution is passed by the Rajya Sabha, it is then presented in the Lok Sabha, which is the lower house of the Parliament. The resolution must be approved by a simple majority in the Lok Sabha.

4. President's Assent: Once the resolution is passed by both houses of Parliament, it is sent to the President of India for his assent. The President's assent is necessary for the resolution to become effective.

5. Creation of the All-India Service: After receiving the President's assent, the central government can proceed with the creation of the new All-India service. The government will establish the rules and regulations governing the service, including recruitment, training, and service conditions.

Importance of Article 312:
Article 312 provides a constitutional mechanism for the creation of All-India services, which are essential for maintaining uniformity and efficiency in the administration of the country. These services play a crucial role in implementing various policies and programs of the central government across different states and union territories. By creating new All-India services, the government can ensure effective governance and better coordination between the center and the states.

In conclusion, creating a new All-India service requires following a constitutional process, and the correct method is through a resolution under Article 312 of the Constitution. This article empowers the Rajya Sabha to pass a resolution by a two-thirds majority, declaring the need for a new All-India service. Once the resolution is passed by both houses of Parliament and receives the President's assent, the government can proceed with the establishment of the new service.

Clean Tillage is a type of tillage practice in agriculture where the soil of the entire field is worked in such a way that no living plant is left undisturbed. This process is done to control weeds, soil-borne pathogens, and pests. The process of clean tillage involves several steps, which are discussed below:

Steps involved in Clean Tillage:

1. Preparing the Field: Before starting the clean tillage process, the field is prepared by removing any debris or plant residues left after the previous crop. This is done to ensure that the soil is free from any obstacles that may interfere with the tillage process.

2. Plowing the Soil: The next step involves plowing the soil using a plow or a disc to loosen the soil and make it ready for planting. This process also helps to mix any remaining plant residues with the soil, which will eventually decompose and add nutrients to the soil.

3. Harrowing the Soil: After plowing, the soil is harrowed to break up any large clumps of soil and to create a level seedbed. This process also helps to incorporate any remaining plant residues into the soil.

4. Seeding or Planting: Once the soil is prepared, seeds or seedlings are planted according to the crop being grown.

Benefits of Clean Tillage:

1. Weed Control: Clean tillage helps to control weeds by disturbing the soil and burying weed seeds that may be present on the surface.

2. Pest Control: Tillage helps to control pests by disturbing their habitat and exposing them to predators and other natural enemies.

3. Soil-borne Pathogen Control: Clean tillage helps to control soil-borne pathogens by burying any infected plant residues that may be present on the surface.

4. Improved Soil Structure: Tillage helps to improve soil structure by loosening compacted soil and creating a better environment for plant growth.

5. Nutrient Management: Tillage helps to mix plant residues into the soil, which eventually decompose and add nutrients to the soil.

In conclusion, Clean Tillage is an important tillage practice in agriculture that helps to control weeds, pests, and soil-borne pathogens while improving soil structure and nutrient management.

Flat Shape of the Universe:

The overall shape of the Universe according to scientific observations is considered to be flat. This conclusion is based on a variety of observations and measurements made by astronomers and cosmologists.

Cosmic Microwave Background Radiation:
One of the key pieces of evidence supporting the flat shape of the Universe comes from the Cosmic Microwave Background Radiation (CMB). The fluctuations in the CMB provide valuable information about the geometry of the Universe, and the data collected indicates that the Universe is flat.

Measurements of Large-Scale Structure:
Observations of the large-scale structure of the Universe, including the distribution of galaxies and galaxy clusters, also support the idea that the Universe is flat. These measurements suggest that the overall geometry of the Universe is consistent with a flat shape.

General Relativity:
The theory of General Relativity, proposed by Albert Einstein, also supports the idea of a flat Universe. According to General Relativity, the geometry of the Universe is determined by the distribution of matter and energy, and in a flat Universe, the total energy density is equal to the critical density.

Conclusion:
In conclusion, based on observations of the CMB, measurements of the large-scale structure of the Universe, and the predictions of General Relativity, scientists have determined that the overall shape of the Universe is flat. This has significant implications for our understanding of the cosmos and the fundamental nature of the Universe.

Explanation:
Article 312 of the Indian Constitution empowers the Rajya Sabha to create new All India Services in the national interest. However, the assertion that the Rajya Sabha can define national interest better is incorrect. Here's why:

A is false: The assertion that the Rajya Sabha under Article 312 is empowered to create new All India Services in the national interest is true.

R is true: The reason that the Rajya Sabha can define national interest better is false. This is because the Constitution of India does not give any specific power to either the Rajya Sabha or the Lok Sabha to define national interest. The Constitution defines national interest as the interest of the nation as a whole, and it is the responsibility of the government to ensure that the national interest is protected. Therefore, both the Rajya Sabha and the Lok Sabha have equal responsibility to protect the national interest.

In conclusion, the correct answer is option D: A is false but R is true.

Assertion (A): Recruitment to the public services is to be regulated by the Acts of appropriate legislatures.

Reason (R): The Constitution does not have provisions to regulate the recruitment of civil servants.

Explanation:

Recruitment to Public Services:
Recruitment to public services is an important aspect of governance. It is necessary to have a well-defined process for the selection and appointment of civil servants to ensure fairness, transparency, and efficiency in the functioning of the government. The recruitment process determines the quality and competence of individuals who will serve in various positions within the public services.

Acts of Appropriate Legislatures:
The recruitment of civil servants is regulated by the Acts of appropriate legislatures. These Acts define the eligibility criteria, selection procedure, reservation policies, and other aspects related to recruitment. For example, in India, the recruitment of civil servants is regulated by the Union Public Service Commission (UPSC) and various state public service commissions, which are established by Acts of Parliament and State Legislatures, respectively.

Constitutional Provisions:
The Constitution of India provides the framework for the recruitment of civil servants. It lays down the broad principles and guidelines for the recruitment process. However, it does not have detailed provisions to regulate the recruitment of civil servants. The Constitution empowers the appropriate legislatures to enact laws and establish commissions for this purpose.

Correct Explanation:
Both the assertion and the reason are individually true, and the reason is the correct explanation of the assertion. The recruitment of civil servants is indeed regulated by the Acts of appropriate legislatures, as mentioned earlier. The Constitution does not have detailed provisions on recruitment, but it provides the constitutional framework for the establishment of appropriate legislatures and the enactment of laws to regulate recruitment.

Conclusion:
Recruitment to the public services is an important aspect of governance, and it is regulated by the Acts of appropriate legislatures. The Constitution provides the framework for recruitment but does not have detailed provisions to regulate it. The reason provided in the assertion is a correct explanation of the assertion. Therefore, the correct answer is option A.

Understanding the Pasupati Seal
The Pasupati Seal is one of the most significant artifacts discovered from the Harappan Civilization, highlighting the artistry and culture of this ancient society.
Composition of the Seal
- The Pasupati Seal is primarily made of steatite, a soft metamorphic rock composed mainly of talc.
- Steatite is favored for its malleability, allowing artisans to carve intricate designs easily.
Characteristics of Steatite
- Softness: Steatite is softer than many other stones, making it easier to carve.
- Durability: Despite its softness, steatite is quite durable when polished, which helps preserve the carvings over time.
- Aesthetic Appeal: The stone has a natural luster and can be polished to a smooth finish, enhancing its visual appeal.
Significance of the Pasupati Seal
- The seal features an image of a deity, often interpreted as a prototype of Lord Shiva, surrounded by animals. This reflects the spiritual and cultural beliefs of the Harappan people.
- Its discovery provides insight into the trade, art, and religious practices of the Harappan Civilization.
Conclusion
The Pasupati Seal's creation from steatite underscores the advanced skills of Harappan artisans. This choice of material not only facilitated intricate designs but also contributed to the seal’s longevity, allowing it to be appreciated by future generations.

Explanation of the Statements
Statement-I discusses the borrowing powers of the Union and State Governments in India concerning Article 292 and Article 293 of the Constitution.
- Union Government (Article 292):
- Can borrow both domestically and internationally.
- Borrowing is subject to the limits specified by the Parliament.
- State Governments (Article 293):
- Limited to borrowing only within the country.
- This reflects a more controlled financial environment for states.
Statement-II pertains to the nature of Public Debt in India.
- Public Debt of India:
- Comprises both internal and external liabilities.
- However, Statement-II incorrectly states that it includes only the liabilities incurred by the Central Government, neglecting the public debt incurred by State Governments.
Correctness of the Statements
- Statement-I:
- Correct, as it accurately describes the borrowing framework for both Union and State Governments.
- Statement-II:
- Incorrect, because it limits the definition of public debt to only the liabilities of the Central Government and omits the debts of State Governments.
Conclusion
The answer to the question is option 'C':
- Statement-I is correct, but Statement-II is incorrect.
This distinction is crucial in understanding the overall framework of public debt management in India.

Understanding Soil Formation
Soil formation is a complex process influenced by multiple factors, including parent rock material and climatic conditions.
Assertion (A) Explanation
- Influence of Parent Rock Material: The mineral composition and structure of the parent rock dictate the types of minerals present in the soil, affecting its fertility and drainage.
- Climatic Conditions: Temperature, precipitation, and seasonal variations impact weathering processes and biological activity, significantly affecting soil development.
Reason (R) Explanation
- Biological Activity: While organisms such as plants, fungi, and bacteria contribute to soil formation through organic matter addition and nutrient cycling, they are not the sole factors.
- Oversimplification: The assertion that soils are solely formed by biological activity overlooks the critical roles played by geological and climatic factors.
Conclusion
- Correct Answer is Option 'C': Assertion (A) is true because soil formation is indeed influenced by parent rock material and climate. However, Reason (R) is false since it inaccurately states that biological activity alone is responsible for soil formation.
In summary, while biological processes are important, they operate alongside geological and climatic factors to contribute to the complex nature of soil formation.

Drip Irrigation:

Drip irrigation is a type of micro-irrigation system that involves dripping water onto the soil at very low rates from a system of small diameter plastic pipes fitted with outlets called emitters. It is used to water crops in small areas or where water is scarce.

Statement Analysis:

1. Drip irrigation is also called Sprinkler irrigation and involves dripping water onto the soil at very low rates from a system of small diameter plastic pipes fitted with outlets called emitters.

This statement is incorrect. Drip irrigation and sprinkler irrigation are two different types of irrigation systems. Sprinkler irrigation involves spraying water over the crops, while drip irrigation involves dripping water onto the soil at very low rates.

2. Water is applied close to plants so that only part of the soil in which the roots grow is wetted.

This statement is correct. Drip irrigation is designed to apply water directly to the roots of the plants, which helps to minimize evaporation and water waste. By applying water close to the plants, only the soil in which the roots grow is wetted, which helps to conserve water.

Conclusion:

Therefore, the correct answer is option B, which states that statement 2 only is correct.

What happened during the Big Bang?

The Big Bang theory is the prevailing cosmological model that explains the origins and evolution of the universe. According to this theory, the universe began as a singularity - a point of infinite density and temperature - and then rapidly expanded and cooled over time. Let's delve into the details of what occurred during the Big Bang:

1. Singularity:
During the initial moments of the Big Bang, all matter and energy in the universe were concentrated into an incredibly small, dense point known as a singularity. This singularity is thought to have contained all the building blocks of the universe, including elementary particles and fundamental forces.

2. Rapid Expansion:
Following the singularity, the universe experienced a rapid expansion known as cosmic inflation. This expansion caused space itself to stretch, carrying matter and energy along with it. This exponential expansion occurred within a fraction of a second, causing the universe to grow exponentially in size.

3. Formation of Particles and Forces:
As the universe expanded and cooled, the energy within it began to convert into matter. During this phase, the fundamental forces of nature (such as gravity, electromagnetism, and the strong and weak nuclear forces) also started to differentiate. Particles, including protons, neutrons, and electrons, formed during this period.

4. Formation of Light Elements:
Within the first few minutes after the Big Bang, the universe cooled down enough for the formation of light atomic nuclei. This process is called nucleosynthesis. The primary elements formed during this phase were hydrogen and helium, with trace amounts of lithium. These light elements serve as the building blocks for the formation of stars and galaxies.

5. Recombination and Cosmic Microwave Background:
Approximately 380,000 years after the Big Bang, the universe cooled sufficiently for electrons to combine with atomic nuclei, forming neutral atoms. This event, known as recombination, allowed photons to travel freely through space. The remnants of these photons, which have been stretched and cooled as the universe expanded, can still be detected today as the cosmic microwave background radiation.

6. Formation of Galaxies and Stars:
As the universe continued to expand and cool, regions of slightly higher density began to attract matter through gravitational forces. These regions eventually collapsed under their own gravity, leading to the formation of galaxies, stars, and other celestial objects.

In summary, the Big Bang theory proposes that the universe began as an incredibly small and dense point. It then rapidly expanded, cooled down, and gave rise to the formation of matter, forces, light elements, and eventually galaxies and stars. The evidence for the Big Bang theory comes from various observations, such as the cosmic microwave background radiation and the abundance of light elements in the universe.

To determine the total number of routes the motorist knows from Bristol to Carlisle, we need to find the product of the number of routes from Bristol to Birmingham, Birmingham to Sheffield, and Sheffield to Carlisle.

Number of routes from Bristol to Birmingham: 4
Number of routes from Birmingham to Sheffield: 3
Number of routes from Sheffield to Carlisle: 2

To calculate the total number of routes from Bristol to Carlisle, we multiply these numbers together.

4 routes * 3 routes * 2 routes = 24 routes

So, the correct answer is option 'D' - 24.

**Problem Solving:**

To solve this problem, we can use a system of linear equations. Let's assume that the number of deer is represented by 'x' and the number of peacocks is represented by 'y'.

**Step 1: Formulate the Equations:**

We are given two pieces of information:

1. The total number of heads is 80.
2. The total number of legs is 200.

From these two pieces of information, we can form two equations:

Equation 1: x + y = 80 (since the total number of heads is 80)

Equation 2: 4x + 2y = 200 (since each deer has 4 legs and each peacock has 2 legs)

**Step 2: Solve the Equations:**

To solve the system of equations, we can use the method of substitution or elimination. In this case, let's solve it using the method of substitution.

From Equation 1, we can express x in terms of y: x = 80 - y

Substituting this value of x into Equation 2, we get:

4(80 - y) + 2y = 200

Simplifying the equation, we have:

320 - 4y + 2y = 200

Combining like terms, we get:

-2y = 200 - 320

-2y = -120

Dividing both sides by -2, we get:

y = 60

**Step 3: Find the Number of Peacocks:**

From our solution, we found that y = 60, which represents the number of peacocks.

Therefore, the correct answer is option D) 60.

Article 312: The provision for the creation of an All India Service is mentioned in Article 312 of the Constitution of India. This article empowers the Parliament to create one or more All India Services if it deems it necessary or expedient for the better administration of the Union or any state.

Explanation:
The creation of All India Services is a significant provision in the Indian Constitution. It aims to ensure a uniform and efficient administrative system throughout the country. Let us understand the details of Article 312 and its implications:

1. Significance of All India Services:
- All India Services, including the Indian Administrative Service (IAS), Indian Police Service (IPS), and Indian Forest Service (IFS), play a crucial role in the governance and administration of the country.
- These services provide a pool of highly skilled and competent officers who serve both at the central and state levels, contributing to effective policy implementation, law and order maintenance, and efficient governance.

2. Empowering the Parliament:
- Article 312 empowers the Parliament to create one or more All India Services.
- The provision grants the Parliament the authority to enact laws for the creation of such services, as it deems necessary or expedient for the better administration of the Union or any state.

3. Conditions for Creation:
- The Parliament can establish an All India Service only if the Rajya Sabha passes a resolution by a majority of not less than two-thirds of the members present and voting.
- This ensures a broad consensus among the members of the Rajya Sabha, representing the states and the Union, before the creation of such services.

4. Common Cadre and Recruitment:
- All India Services have a common cadre that allows officers to be appointed to different states or the Union.
- The recruitment, training, and career progression of officers in these services are regulated by the central government through the Union Public Service Commission (UPSC).

5. Service Conditions:
- The service conditions of All India Service officers, including their pay, allowances, and pension, are determined by the Parliament.
- This ensures uniformity across the country and prevents disparities in the working conditions of officers serving in different states.

Conclusion:
Article 312 of the Indian Constitution empowers the Parliament to create All India Services, which serve as a vital pillar of the administrative machinery. This provision ensures the availability of capable and skilled officers who contribute to efficient governance and the better administration of both the Union and the states.

1. Ashoka Pillar, Sarnath: National Emblem of India
The Ashoka Pillar at Sarnath is correctly matched as it is indeed the National Emblem of India. It features four lions standing back to back mounted on a circular base. This emblem symbolizes the Lion Capital of Ashoka, which is a sculpture of four lions standing back to back, originally erected atop the Ashoka Pillar at Sarnath.

2. Ashoka Pillar, Allahabad: Contains the inscriptions of Samudragupta
The Ashoka Pillar at Allahabad is incorrectly matched in the given pairs. The pillar at Allahabad is famous for the inscriptions of Ashoka and not Samudragupta. This pillar contains inscriptions recording the imperial orders of Ashoka.

3. Bharhut Stupa: Contains numerous Jataka tales
The Bharhut Stupa is correctly matched as it is known for its sculptural art depicting numerous Jataka tales. These tales are stories of the previous lives of Gautama Buddha.

4. Amaravati Stupa: Transformed from a Hinayana shrine to a Mahayana shrine
The Amaravati Stupa is correctly matched as it was originally built as a Hinayana shrine but later transformed into a Mahayana shrine. This stupa is known for its intricate carvings and sculptures depicting various Buddhist motifs and narratives.
In conclusion, out of the four pairs given, three are correctly matched - Ashoka Pillar, Sarnath; Bharhut Stupa; Amaravati Stupa. Only one pair, Ashoka Pillar, Allahabad, is incorrectly matched as it does not contain the inscriptions of Samudragupta but of Ashoka.

Explanation:

1. Shaft of Ashokan pillars:
- The statement that the shafts of Ashokan pillars are always plain and smooth, and they taper upwards is correct. The shafts of Ashokan pillars are indeed known for their simplicity and elegant design, tapering towards the top.

2. Capitals of Ashokan pillars:
- The statement that the capitals of Ashokan pillars are shaped like a gently arched bell formed of lotus petals is also correct. The capitals of Ashokan pillars are distinctive in their design, resembling a bell with lotus petals arranged in an arch.

3. Crowning animals on Ashokan pillars:
- The statement that the crowning animals on Ashokan pillars are always seated and chiselled as a single piece with the abaci is incorrect. The crowning animals on Ashokan pillars can vary, with some being seated while others are standing. Additionally, they are not always chiselled as a single piece with the abaci.
Therefore, the correct answer is option B) 1 and 2 Only, as the first two statements accurately describe the characteristics of Ashokan pillars.