The correct answer is: a) Changlang
Changlang district is one of the 20 districts of Arunachal Pradesh, India. It is located in the eastern part of the state and is bordered by Assam to the south, Nagaland to the west, and Myanmar to the north and east. The district has a population of over 300,000 people and its headquarters is at Changlang town.
Changlang district is known for its coal reserves. The coal deposits in the district are estimated to be over 1 billion tonnes. The coal is of good quality and is used in the power plants in the state. The coal mining industry in the district is a major source of employment for the people of the district.
The other options are incorrect because:
- East Siang district is known for its tea gardens.
- Tawang district is known for its Buddhist monasteries.
- West Kameng district is known for its scenic beauty.