The correct answer is A) Limestone.
Limestone is a sedimentary rock composed mostly of calcium carbonate (CaCO3). It is the most common type of rock found in the Earth’s crust and is used in a variety of industries, including construction, agriculture, and manufacturing.
Limestone is used in the production of cement because it is a source of calcium oxide (CaO), which is one of the main ingredients in cement. Calcium oxide is produced by heating limestone at high temperatures, which causes it to decompose into calcium carbonate and carbon dioxide. The calcium carbonate is then combined with silica (SiO2) and alumina (Al2O3) to form cement clinker, which is the main ingredient in cement.
Bauxite is an ore of aluminum that is used in the production of aluminum metal. It is not used in the production of cement.
Iron ore is an ore of iron that is used in the production of iron and steel. It is not used in the production of cement.
Copper is a metal that is used in a variety of industries, including construction, electronics, and manufacturing. It is not used in the production of cement.