The correct answer is: Option B. Nalanda.
Pant (Rajgir) Wildlife Sanctuary is situated in Nalanda district of Bihar. It is a 100 square kilometer sanctuary that was established in 1976. The sanctuary is home to a variety of wildlife, including tigers, leopards, elephants, deer, and monkeys. It is also a popular tourist destination, with many visitors coming to see the ruins of the ancient city of Rajgir.
The other options are incorrect. Gaya is a district in Bihar, but it is not home to Pant (Rajgir) Wildlife Sanctuary. Nalanda is the district that is home to the sanctuary. Kaimur is a district in Bihar, but it is not home to Pant (Rajgir) Wildlife Sanctuary. Madhepura is a district in Bihar, but it is not home to Pant (Rajgir) Wildlife Sanctuary.