The correct answer is A. 260.
Coal reserves in Bihar on January 1, 2003 were 260 million tonnes. This is according to the Ministry of Coal, Government of India. The coal reserves are located in the Jharia coalfield, which is the largest coalfield in India. The Jharia coalfield is located in the Dhanbad district of Jharkhand state.
The coal reserves in Bihar are of high quality and are used to generate electricity and produce steel. The coal reserves are also used to produce coke, which is used in the iron and steel industry.
The coal reserves in Bihar are a valuable resource and are important for the economy of the state. The coal reserves are also important for the energy security of India.
The other options are incorrect. Option B is incorrect because the coal reserves in Bihar on January 1, 2003 were 260 million tonnes, not 360 million tonnes. Option C is incorrect because the coal reserves in Bihar on January 1, 2003 were 260 million tonnes, not 160 million tonnes. Option D is incorrect because the coal reserves in Bihar on January 1, 2003 were 260 million tonnes, not 210 million tonnes.