His principle forte was social and religious reform. He relied upon legislation to do away with social ills and work unceasingly for the eradication of child marriage and the purdah system. To encourage consideration of social problems on a national scale, he inaugurated the Indian National Social Conference, which for many years met for its annual session alongside the Indian National Congress. [1996]

The reference in this passage is to:

1) Ishwar Chandra Vidyasagar
2) Behramji Merwanji Malabari
3) Mahadev Govind Ranade
4) B.R. Ambedkar