Solution:

Statues of Communist leaders, S.A. Dange and A.K. Gopalan, and the socialist leader, Acharya Narendra Deva, were unveiled in the Parliament House on December 10, 2004, by the Prime Minister, Manmohan Singh.

Shripad Amrit Dange was a revolutionary, a dedicated labor leader and a parliamentarian who played a major role in shaping and molding the trade union movement in the country.

A.K. Gopalan was a distinguished freedom fighter and social reformer who worked for the downtrodden. He was an outstanding parliamentarian, a popular leader of the working class and one of the founders of the Communist movement in the country.

Acharya Narendra Deva was popularly known as the Father of Indian Socialism.

A freedom fighter, he devoted his entire life to the growth, development and propagation of the ideals of democratic socialism.