Correct option is C
Statement 1 is incorrect because Vikramshila University was actually located in the Bhagalpur district of Bihar, not Banka. It is situated near the town of Antichak.
Statement 2 is incorrect as well. The university was established by King Dharmapala, not Gopala I, of the Pala dynasty in the late 8th or early 9th century CE.
Statement 3 is correct. The Vajrayana sect of Buddhism did flourish at Vikramshila, which was one of the prominent centers of Buddhist learning alongside Nalanda.
Statement 4 is correct. The university offered a variety of subjects, including Astronomy, Logic, Law, Grammar, and Philosophy.
Vikramshila was a major learning center, particularly famous for its teachings of Tantric Buddhism, and played an essential role in the development of Buddhism in the region.