Which of the following universities in ancient India had six colleges each under them and had a lot of exchange of ideas between them? Choose the correct answer from the options given below.

Among these, Nalanda and Vikramashila each had six colleges under them with lively exchange of ideas between scholars.

Sridhanya Katak, though an ancient seat of learning, is not described with this six-college structure.

Nalanda in Bihar was a great Buddhist residential university drawing students from across Asia.

Takshashila, an earlier centre, is not the pair meant by this six-college description.

Vikramashila, founded by King Dharmapala, specialised in Tantric Buddhist studies.

Both Nalanda and Vikramashila were destroyed in the invasions of the late twelfth century.