Explanation:

To understand why the correct answer is option 'C', we need to understand the concept of normalization in database design.

Normalization is a process of organizing data in a database to reduce redundancy and dependency. It helps to eliminate data anomalies and inconsistencies, and ensure data integrity and consistency.

In normalization, there are several normal forms, each with its own rules and requirements. The most commonly used normal forms are:

1. First normal form (1NF)
2. Second normal form (2NF)
3. Third normal form (3NF)
4. Fourth normal form (4NF)
5. Fifth normal form (5NF)

Now, let's understand each normal form in detail and see how they relate to the question asked.

1. First normal form (1NF):

First normal form (1NF) is the simplest form of normalization, which requires that a relation must have atomic values. In other words, each attribute of a relation must contain only a single, indivisible value.

For example, consider a relation that stores information about students and their courses:

Student ID | Name | Course 1 | Course 2 | Course 3
--------------------------------------------------
1 | John | Math | Science | English
2 | Mary | Science | History | NULL

This relation is not in 1NF because the attributes Course 1, Course 2, and Course 3 contain multiple values, separated by commas. To bring this relation to 1NF, we need to split the multivalued attributes into separate relations:

Student ID | Name
------------------
1 | John
2 | Mary

Student ID | Course
--------------------
1 | Math
1 | Science
1 | English
2 | Science
2 | History

2. Second normal form (2NF):

Second normal form (2NF) requires that a relation must be in 1NF and every non-key attribute must be functionally dependent on the entire primary key.

For example, consider a relation that stores information about orders and their items:

Order ID | Customer ID | Item ID | Item Name | Quantity | Price
----------------------------------------------------------------
1 | 100 | 1 | Widget | 2 | $10
1 | 100 | 2 | Gadget | 1 | $20
2 | 200 | 2 | Gadget | 3 | $20

This relation is not in 2NF because the non-key attribute Item Name is functionally dependent on the Item ID, which is only part of the primary key. To bring this relation to 2NF, we need to split it into two relations:

Order ID | Customer ID | Item ID | Quantity | Price
----------------------------------------------------
1 | 100 | 1 | 2 | $10
1 | 100 | 2 | 1 | $20
2 | 200 | 2 | 3 | $20

Item ID | Item Name
-------------------
1 | Widget
2 | Gadget

3. Third normal form (3NF):

Third normal form (3NF) requires that a relation must be in 2NF and every non-key attribute must be functionally dependent on the primary key, and nothing but the primary key.

For example, consider a relation that stores information about employees and