The correct answer is (a) K.M. Munshi.
K.M. Munshi was a freedom fighter, lawyer, and politician who played a major role in the drafting of the Indian Constitution. He was the Chairman of the Fundamental Rights Sub-Committee of the Constituent Assembly. The Sub-Committee was responsible for drafting the chapter on Fundamental Rights in the Constitution.
The other options are incorrect.
(b) Sardar Patel was the Deputy Prime Minister of India and the Home Minister of India. He was responsible for the integration of the princely states into the Indian Union.
(c) Rajendra Prasad was the first President of India. He was also the President of the Constituent Assembly.
(d) J.B. Kripalani was a freedom fighter and politician. He was the President of the Indian National Congress from 1947 to 1950.