The biggest stadium of Bihar is located at which place in the state?

The correct answer is C. Patna.

The Jawaharlal Nehru Stadium is a multi-purpose stadium in Patna, India. It is the largest stadium in Bihar and is the home ground of the Bihar cricket team. The stadium has a capacity of 35,000 people and was built in 1974. It has hosted several international cricket matches, including a Test match between India and Australia in 1986.

The other options are incorrect. Banka is a town in Bihar. Gaya is a city in Bihar. Kaimur is a district in Bihar.