Correct option is B. Dr BR Ambedkar
Dr B.R. Ambedkar, who organised the dalits into the Depressed Classes Association in 1930, clashed with Mahatma Gandhi at the second Round Table Conference by demanding separate electorates for dalits. When the British government conceded Ambedkars demand, Gandhiji began a fast unto death. He believed that separate electorates for dalits would slow down the process of their integration into society. Ambedkar ultimately accepted Gandhijis position and the result was the Poona Pact of September 1932.It gave the Depressed Classes (later to be known as the Schedule Castes) reserved seats in provincial and central legislative councils, but they were to be voted in by the general electorate. The dalit movement, however, continued to be apprehensive of the Congress led national movement.