The correct answer is option 3. Subhash Chandra Bose founded the "Forward Block" party. The other options are incorrect.
Option 1 K.M. Munshi was a prominent Indian independence activist and writer, but he did not found the "Forward Block" party.
Option 2 Motilal Nehru was also a prominent Indian independence activist and lawyer, but he did not found the "Forward Block" party.
Option 4 Bal Gangadhar Tilak was a prominent Indian nationalist leader, but he did not found the "Forward Block" party.
It is important to note that Subhash Chandra Bose founded the "Forward Block" party in 1939 as a faction within the Indian National Congress, with the aim of achieving complete independence from British rule.