Explanation:

The correct answer is (2) 1916. Banaras Hindu University (BHU) was founded by the great nationalist leader and educationist Pandit Madan Mohan Malaviya, with the cooperation of Annie Besant, in 1916. Its establishment was formalized by the B.H.U. Act of 1915. Option (1) 1875 is incorrect; this year is notable for the founding of the Muhammadan Anglo-Oriental College (later Aligarh Muslim University), not BHU. Options (3) 1921 and (4) 1930 are also incorrect; by these years, BHU was already a well-established and functioning institution, having been founded several years prior.