Detailed Explanation:

Correct Answer: Option 4 (Dr. Sachchidananda Sinha)

The Constituent Assembly of India first met on 9 December 1946. Since the permanent President had not yet been elected, Dr. Sachchidananda Sinha was appointed as the Provisional President (Temporary Chairman). Later, Dr. Rajendra Prasad was elected as the permanent President of the Constituent Assembly on 11 December 1946.

✅ Dr. Sachchidananda Sinha is Correct: He served as the first and Provisional President of the Constituent Assembly.

❌ C. Rajagopalachari: He was the last Governor-General of India, not the Provisional President.

❌ Dr. B.R. Ambedkar: He was the Chairman of the Drafting Committee.

❌ T.T. Krishnamachari: He was an important member of the Constituent Assembly but not its Provisional President.

Short Notes: Constituent Assembly of India

• The Constituent Assembly first met on 9 December 1946.

• Dr. Sachchidananda Sinha served as the Provisional President.

• Dr. Rajendra Prasad became the permanent President on 11 December 1946.

• Dr. B.R. Ambedkar was Chairman of the Drafting Committee.

• The Drafting Committee was formed on 29 August 1947.

• The Constitution was adopted on 26 November 1949.

• The Constitution came into force on 26 January 1950.

• The Constituent Assembly took about 2 years, 11 months, and 18 days to complete the Constitution.