The correct answer is option 1, Dr. Rajendra Prasad. He was the President of the Constituent Assembly of India. The Constituent Assembly was responsible for drafting the Constitution of India, which took place from December 1946 to November 1949. Dr. Rajendra Prasad, a prominent leader of the Indian National Congress, was elected as the President of the Constituent Assembly on 11th December 1946. He played a crucial role in guiding the assembly`s proceedings and ensuring that the Constitution of India was formulated in a fair and inclusive manner. Dr. Rajendra Prasad later served as the first President of the Republic of India from 1950 to 1962.