The Jharia coalfield, the most important source of coking coal in India, is located in

Jharia, in the Dhanbad district of Jharkhand, lies in the Damodar valley and has the best deposits of coking coal used in the steel industry. Raniganj in West Bengal is the second major coalfield of the same valley, Talcher in Odisha and Korba in Chhattisgarh are important for non-coking coal used for power generation, so Jharkhand is the right answer.