The correct option is B Mahatma Gandhi
Harijan Sevak Sangh was a non-profit organisation founded by Mahatma Gandhi in 1932 to eradicate untouchability in India. It was born out of the historic Poona Pact between Mahatma Gandhi and Babasaheb Ambedkar. Mahatma Gandhi objected to the provision of separate electorates for the Scheduled Castes granted in the Communal Award of 1932, which in his view separated them from the whole Hindu community.