The correct answer is: b) Coal
Coal is a fossil fuel formed from the remains of ancient plants that have been buried and subjected to intense heat and pressure over millions of years. It is a non-renewable resource and is used to generate electricity, produce steel, and make other products.
Limestone is a sedimentary rock composed mainly of calcium carbonate. It is formed when the remains of marine organisms, such as coral and shellfish, are buried and compacted over time. Limestone is used in a variety of construction materials, including concrete, cement, and lime.
Iron ore is a mineral that contains iron. It is the primary raw material used to make iron and steel. Iron ore is found in rocks and minerals all over the world. The most common types of iron ore are hematite, magnetite, and taconite.
Copper is a metal that is found in nature. It is a reddish-brown color and is a good conductor of electricity. Copper is used in a variety of products, including electrical wiring, plumbing, and coins.
Coal is the most important mineral found in the southern regions of Bihar. It is found in the Jharia coalfield, which is one of the largest coalfields in India. The Jharia coalfield is located in the Damodar Valley, which is a major industrial region in India.