Who was the founder of Nalanda University?

The correct answer is Kumargupta.

Nalanda University History

Nalanda University was established in the 5th century CE, and became a prominent hub for Buddhist studies, attracting students and scholars from various regions. Kumargupta I of the Gupta dynasty founded Nalanda Mahavihara in 427 CE located in present-day Rajgir, Bihar. 

• Contribution by Palas: The Palas were known to be Buddhists. An inscription from Nalanda records that Dharmapala & Devapala gifted villages for the upkeep of the monastery.
• Nalanda received royal patronage from Harshavardana (606-648 C.E.) and the 7th-century king of Assam, Bhaskaravarma.
• Along with this, it got grants from many foreign rulers as well.
• Destruction: The university was destroyed at the end of the 12th century by Bakhtiyar Khilji. 
• Rediscovery of site: The Nalanda University site was first rediscovered in 1812 by Scottish surveyor Francis Buchanan-Hamilton. Although he noted the presence of ruins and Buddhist images, he did not initially connect them to the famed Nalanda University.
• This connection was later made by Sir Alexander Cunningham in 1861, who identified the site as the ancient university.