The correct option is A Nalanda
Nalanda University is located near Rajgriha in present day Bihar. It could also be considered as the best place to learn Buddhist teachings. Subjects like Logic, Grammar, Philosophy, Astronomy, literature, Hinduism, medicine, the Vedas were offered as well. Nalanda had famous libraries like Ratnasagar, Ratnadadhi and Ratnaranjak. Valabhi University was located near modern-day Gujarat and near the Takshshila university. It was a Buddhist monastery. The university specialises in religious learning, law, medicine, politics or the Arthashastra. Takshshila is located about 50 Km west of modern-day Rawalpindi in Pakistan. It regained its importance during the rule of Kanishka.