<Li> Committees presented reports on issues . </Li> <Li> B.N. Rau prepared an initial draft based on the reports and his research into the constitutions of other nations . </Li> <Li> The drafting committee, chaired by B.R. Ambedkar, presented a detailed draft constitution which was published for public discussion . </Li> <Li> The draft constitution was discussed, and amendments proposed and enacted . </Li>

Who was appointed as the chairman of the drafting committee of the constitution