The correct answer is: a) Nalanda.
Nalanda was a Mahavihara, a large Buddhist monastery in the Indian subcontinent. It was located in the ancient kingdom of Magadha, on the northeastern side of the Ganges River about 95 kilometers (59 mi) southeast of Patna in the modern Indian state of Bihar. The site is a UNESCO World Heritage Site.
Nalanda was a center of learning from the fifth century CE to the twelfth century CE. It was one of the first universities in the world, and it attracted students from all over Asia. The university was destroyed by the Muslim invaders in 1197 CE.
The ruins of Nalanda are located in the Nalanda district of Bihar. The site is a major tourist attraction, and it is also a place of pilgrimage for Buddhists.
The other options are incorrect because:
- b) Patna is a city in the Indian state of Bihar. It is the capital of Bihar and the 19th most populous city in India.
- c) Gaya is a city in the Indian state of Bihar. It is a major pilgrimage site for Hindus and Buddhists.
- d) Bodh Gaya is a town in the Indian state of Bihar. It is the place where Gautama Buddha attained enlightenment.