The correct answer is Pawapuri.
Pawapuri is a town and a notified area committee in Nalanda district in the Indian state of Bihar. It is located on the banks of the Phalgu River, about 100 kilometres (62 mi) south of Patna, the capital of Bihar. Pawapuri is a major pilgrimage site for Jains, as it is the place where Mahavira, the 24th Tirthankara, attained moksha (liberation).
The town is home to a number of Jain temples, including the Mahavira temple, which is one of the most important Jain temples in India. The temple complex is spread over an area of about 100 acres (40 ha) and includes a number of shrines, as well as a museum.
Pawapuri is also a popular tourist destination, and is known for its scenic beauty. The town is surrounded by hills and forests, and the Phalgu River flows through the town.
The other options are incorrect because they are not princely states in Bihar. Dumraon is a town and a notified area committee in Rohtas district in the Indian state of Bihar. Ramgarh is a town and a notified area committee in Hazaribagh district in the Indian state of Jharkhand. Rajnagar is a town and a notified area committee in Vaishali district in the Indian state of Bihar.