The correct answer is D. Nalanda.
Nalanda was an ancient university in India, located in the present-day state of Bihar. It was one of the most important centers of learning in the world for over 700 years, from the 5th to the 12th centuries. The university was founded by the Gupta dynasty and attracted students from all over Asia. It was known for its studies in Buddhist philosophy, logic, and grammar.
Panini was a Sanskrit grammarian who lived in the 5th century BCE. He is considered the father of Sanskrit grammar and his work, the Ashtadhyayi, is one of the most important texts in the history of linguistics. The Ashtadhyayi is a comprehensive grammar of Sanskrit that covers all aspects of the language, including phonology, morphology, syntax, and semantics.
It is believed that Panini studied at Nalanda University. There is no direct evidence to support this claim, but there are several reasons to believe that it is likely. First, Nalanda was one of the most important centers of learning in India at the time. Second, Panini’s work is highly technical and would have required a deep understanding of Sanskrit grammar. Third, Nalanda was known for its studies in grammar.
Therefore, it is likely that Panini studied at Nalanda University. His work is a testament to the high level of learning that was achieved at the university.