The correct answer is A) P. Krishna Pillai.
P. Krishna Pillai was a prominent Indian trade unionist and politician. He was one of the founding members of the All India Trade Union Congress (AITUC) and served as its president from 1929 to 1931. He was also a member of the Indian National Congress and the Communist Party of India.
K.C. George was a trade unionist and politician from Kerala, India. He was the leader of the Kerala State Committee of the Communist Party of India (Marxist) and a member of the Kerala Legislative Assembly.
A.K. Gopalan was a trade unionist and politician from Kerala, India. He was the leader of the All India Trade Union Congress (AITUC) and a member of the Communist Party of India.
C. Kesavan was a trade unionist and politician from Kerala, India. He was the leader of the Indian National Trade Union Congress (INTUC) and a member of the Indian National Congress.
P. Krishna Pillai was the most prominent leader among the four who played a key role in the formation of the All India Trade Union Congress (AITUC) in Kerala. He was a founding member of the AITUC and served as its president from 1929 to 1931. He was also a member of the Indian National Congress and the Communist Party of India.