Answer and Explanation:
The correct answer is (b) Only two
Bharatiya Jana Sangh - Dr. Shyama Prasad Mukherjee: Correct. Dr. Shyama Prasad Mukherjee was the founder and the leader of the Bharatiya Jana Sangh.
Socialist Party - C. Rajagopalachari: Incorrect. C. Rajagopalachari was associated with the Swatantra Party, not the Socialist Party. The Socialist Party had leaders like Dr. Ram Manohar Lohia.
Congress for Democracy - Jagjivan Ram: Correct. Jagjivan Ram was one of the leaders who founded the Congress for Democracy.
Swatantra Party - Acharya Narendra Dev: Incorrect. The Swatantra Party was founded by C. Rajagopalachari. Acharya Narendra Dev was associated with the Socialist Party.
Therefore, only two pairs are correctly matched.