The correct answer is: A. Limestone
Limestone is a sedimentary rock composed mainly of calcium carbonate (CaCO3). It is the most common sedimentary rock on Earth, and the most widely used rock in construction. Limestone is formed when calcium carbonate-rich water, such as from springs or rivers, precipitates out of solution and forms solid deposits. These deposits can accumulate over time to form thick layers of limestone.
Limestone is a versatile rock that can be used for a variety of purposes. It is a popular building material, and is used to make concrete, bricks, and other construction materials. Limestone is also used in the manufacture of paper, glass, and other products. It is also a valuable source of calcium carbonate, which is used in a variety of industries, including agriculture, food processing, and pharmaceuticals.
The Rajban, Bharti, and Korga areas of Sirmaur district are known for their limestone deposits. These deposits are of high quality and are used to produce a variety of products. The limestone industry is an important part of the economy of Sirmaur district.
The other options are incorrect because:
- Gold is a precious metal that is found in ores. It is not found in limestone.
- Gypsum is a mineral that is used to make plaster and other products. It is not found in limestone.
- Silver is a precious metal that is found in ores. It is not found in limestone.