The correct answer is: B. Marafari Airport
Marafari Airport is a military airport located in Marafari, Bihar, India. It is used by the Indian Air Force for training and operational purposes. The airport is also used by the Indian Army for helicopter operations.
Gaya International Airport is a civil airport located in Gaya, Bihar, India. It is the main airport serving the state of Bihar. The airport is operated by the Airports Authority of India.
Darbhanga Airport is a civil airport located in Darbhanga, Bihar, India. It is the second-largest airport in Bihar after Gaya International Airport. The airport is operated by the Airports Authority of India.
Raxaul Airport is a civil airport located in Raxaul, Bihar, India. It is a small airport with limited facilities. The airport is operated by the Airports Authority of India.
Marafari Airport is the only airport in Bihar that is used as a defence airport. The other three airports are used for civil purposes.