The correct answer is A. Barauni.
Hindustan Fertilizer Corporation Limited (HFC) is a government-owned fertilizer company in India. It was established in 1961 and is headquartered in New Delhi. HFC has a number of factories located across India, including one at Barauni in Bihar. The Barauni fertilizer plant is one of the largest in India and produces a variety of fertilizers, including urea, ammonium nitrate, and diammonium phosphate.
The other options are incorrect. Munger is a city in Bihar that is known for its silk industry. Fatuha is a town in Bihar that is located on the banks of the Ganges River. Gaya is a city in Bihar that is known for its Buddhist temples.