The correct answer is D. Eastern Singhbhum.
Eastern Singhbhum is a district in the Indian state of Jharkhand. It is one of the richest districts in Jharkhand in terms of mineral resources, including coal, iron ore, and graphite. The district is home to the Deogarh coalfield, which is one of the largest coalfields in India. The district is also home to the Dalma iron ore mine, which is one of the largest iron ore mines in India. Graphite is a mineral that is used in a variety of products, including pencils, lubricants, and batteries. The district of Eastern Singhbhum is a major producer of graphite.
The other options are incorrect. Palamu is a district in the Indian state of Jharkhand. It is not a major producer of graphite. Bokaro is a district in the Indian state of Jharkhand. It is a major producer of coal, but it is not a major producer of graphite. Ranchi is the capital of the Indian state of Jharkhand. It is not a major producer of graphite.