Step 1: Understanding the Constitutional Advisor's Role:
The role of Constitutional Advisor to the Constituent Assembly of India was significant in advising on the framing of the Constitution. This advisor was instrumental in shaping the legal framework of independent India.
Step 2: Detailed Explanation of the Options:
- (A) Dr. Rajendra Prasad: While Dr. Rajendra Prasad was the first President of India, he was not the Constitutional Advisor to the Constituent Assembly.
- (B) Dr. B.R. Ambedkar: Dr. B.R. Ambedkar is known as the principal architect of the Indian Constitution but was not the Constitutional Advisor.
- (C) B.N. Rao: This is the correct answer. B.N. Rao was the Constitutional Advisor to the Constituent Assembly and played a key role in drafting the Constitution.
- (D) Jawaharlal Nehru: Nehru, while being the first Prime Minister of India, was not the Constitutional Advisor to the Constituent Assembly.
Step 3: Final Conclusion:
The correct answer is (C) B.N. Rao, as he served as the Constitutional Advisor to the Constituent Assembly of India.