The correct answer is (a) Surya Sen.
Surya Sen was an Indian revolutionary who led the Chatgaon Armoury raid in 1930. The raid was an attempt to seize weapons from the British-controlled armoury in Chatgaon, now in Bangladesh. The raid was unsuccessful, but it was a major turning point in the Indian independence movement.
Chandrashekhar Azad was an Indian revolutionary who was involved in several armed uprisings against the British Raj. He was killed in an encounter with the police in 1931.
Bhagat Singh was an Indian revolutionary who was involved in the assassination of a British police officer in 1928. He was hanged by the British in 1931.
Ambika Chakravarti was an Indian revolutionary who was involved in the Kakori train robbery in 1925. He was hanged by the British in 1927.