Buddhist monastery which was referred by Fa-Hien was found in Sitagarh mountain of

The correct answer is A. Hazaribagh.

Fa-Hien was a Chinese Buddhist monk who traveled to India in the 5th century CE. He visited many Buddhist monasteries in India, including one in Sitagarh mountain in Hazaribagh district of Jharkhand. The monastery was built in the 3rd century BCE and was one of the largest and most important Buddhist monasteries in India. It was destroyed by the Huns in the 5th century CE.

The other options are incorrect. B. Palamu is a district in Jharkhand. C. Koderma is a town in Jharkhand. D. None of these is the correct answer.