Explanation:

• - Option 1: Jawaharlal Nehru was not the Chairman of the State Committee. Dr. B.R. Ambedkar was the Chairman of the Drafting Committee. This is incorrect.
• - Option 2: Sachidanand Sinha was the temporary Chairman of the Constituent Assembly, while B.N. Rau was the Constitutional Advisor. This is incorrect.
• - Option 3: The Constituent Assembly took 2 years, 11 months, and 18 days to draft the Constitution. This is correct.
• - Option 4: The Constituent Assembly met for the first time on December 9, 1946. This is correct.
• - Option 1 and 2 are both incorrect. However, since you identified Option 2 as incorrect first, it also fits the bill.
• Correct Answer: Option 2: SachidanandSinha was the Constitutional Advisor to the Constituent Assembly.