During British rule, Ambedkar had been a political opponent of the Indian National Congress. On whose advice, Ambedkar was asked to join the Union Cabinet?

M.K. Gandhi

The correct answer is Option (4) → M.K. Gandhi

B.R. Ambedkar, a prominent leader and social reformer who championed the rights of the Dalits (formerly known as untouchables), had been a political opponent of the Indian National Congress during British rule. He had his own distinct political agenda and had differences with the Congress on various issues, particularly related to the rights of the Dalits.

However, recognizing Ambedkar's expertise and leadership, and to ensure fair representation of various communities in the government, Mahatma Gandhi, who was a key figure in the Indian National Congress and the Indian independence movement, advised Ambedkar to join the Union Cabinet. This move was part of efforts to create a more inclusive government and address the concerns and rights of marginalized communities, particularly the Dalits. Gandhi's advice was aimed at promoting social justice and representation within the government, even if there were past political differences. Ambedkar ultimately accepted the offer and served as the first Law Minister of independent India, where he played a crucial role in the framing of the Indian Constitution.

So, the correct option is [4].