Which one of the following leaders played an important role in the integration of princely states with India?

Sardar Vallabh Bhai Patel

The correct answer is option (1) - Sardar Vallabh Bhai Patel

Sardar Patel was India’s Deputy Prime Minister and the Home Minister during the crucial period immediately following Independence. He played a historic role in negotiating with the rulers of princely states firmly but diplomatically and bringing most of them into the Indian Union.

More about Sardar Vallabhbhai Patel (1875-1950):
He was a leader of the freedom movement & a Congress leader from Gujarat.
He was a follower of Mahatma Gandhi and participated in various movements with him.
He was the Deputy Prime Minister and first Home Minister of independent India.
Also, he was a member of important committees of the Constituent Assembly on Fundamental Rights, Minorities, Provincial Constitution, etc.
He played an important role in the integration of Princely States with India.