The correct answer is option 'A', Part III.

The Indian Constitution guarantees fundamental rights to the people in Part III. Part III of the Constitution contains the fundamental rights that are considered essential for the growth and development of the individual. These rights are enforceable by the courts, and any law or action that violates these rights can be challenged and struck down.

Here is a detailed explanation of Part III of the Indian Constitution:

1. Introduction:
- Part III of the Constitution is titled "Fundamental Rights."
- It consists of Articles 12 to 35.

2. Key Features of Part III:
- Part III guarantees certain basic rights to the citizens of India.
- These rights are considered fundamental as they are essential for the overall development and protection of individuals.
- The fundamental rights are enforceable by the courts, and any law or action that violates these rights can be challenged and struck down.

3. Fundamental Rights:
- Part III includes several fundamental rights that protect various aspects of an individual's life and liberty.
- Some of the fundamental rights guaranteed by Part III include:
- Right to Equality (Articles 14-18): This includes equality before the law, prohibition of discrimination, and equality of opportunity.
- Right to Freedom (Articles 19-22): This includes the freedom of speech and expression, the freedom to assemble peacefully, the freedom to form associations or unions, etc.
- Right against Exploitation (Articles 23-24): This includes the prohibition of human trafficking, forced labor, and child labor.
- Right to Freedom of Religion (Articles 25-28): This includes the freedom to practice, profess, and propagate any religion.
- Cultural and Educational Rights (Articles 29-30): This includes the right to preserve one's language, script, and culture, and the right of minorities to establish and administer educational institutions.
- Right to Constitutional Remedies (Article 32): This grants individuals the right to move the Supreme Court for the enforcement of their fundamental rights.

4. Significance:
- Part III of the Constitution is considered the cornerstone of individual liberty and democracy in India.
- It ensures that citizens have certain basic rights that protect their dignity, freedom, and equality.
- These rights enable individuals to lead a meaningful and fulfilling life and act as a check on the power of the state.

In conclusion, Part III of the Indian Constitution guarantees fundamental rights to the people. These rights are considered essential for the growth and development of individuals and are enforceable by the courts. They protect various aspects of an individual's life and liberty, and any law or action that violates these rights can be challenged and struck down.