Who among the following was the first Chairman of the Backward Class Commission?

The correct answer is (b), Kakasaheb Kalelkar.

Kakasaheb Kalelkar was a social reformer and politician from India. He was the first Chairman of the Backward Class Commission, which was set up in 1953 to investigate the condition of the backward classes in India and to recommend measures for their advancement.

The other options are incorrect. Jagjiwan Ram was a politician who served as the Deputy Prime Minister of India from 1979 to 1980. B.R. Ambedkar was a social reformer, politician, and the principal architect of the Constitution of India.