Who was appointed as the Constitutional Advisor (Legal Advisor) to the Constituent Assembly, responsible for preparing the initial structural framework of the draft Constitution?

Explanation

Sir B.N. Rau was appointed as the Constitutional Advisor to the Constituent Assembly. He prepared the initial draft of the Constitution after analyzing various global legal systems, which was then systematically examined and refined by Dr. Ambedkar's Drafting Committee. S.N. Mukherjee was the chief draftsman of the Constitution in the Assembly.