Correct Answer: (a) Vikramshila
Solution:during the Buddhist period, some the most important centres of learning in India were Nalanda, Vikramshila and Vallabhi. These centres of learning were not only popular among the different Janapadas, from where students came for learning but also attracted students from abroad i.e. China, Japan, Tibet and other countries of South-East Asia. Some of the educational centres like Taxila and Nalanda enjoyed the status of Universities.