Limestone mined in Sikkim is primarily utilized in:

The cement industry
Construction
Steel production
Fertilizer manufacturing

The correct answer is: a) The cement industry.

Limestone is a sedimentary rock composed mainly of calcium carbonate (CaCO3). It is the most common type of rock in the world, and it is used in a variety of industries, including the cement industry, construction, steel production, and fertilizer manufacturing.

In the cement industry, limestone is used to make cement, which is a binding agent that is used in concrete and other construction materials. Limestone is also used in the production of steel, as it is a source of calcium. In fertilizer manufacturing, limestone is used to neutralize acidic soils.

Limestone is a valuable resource that is used in a variety of industries. It is a non-renewable resource, and it is important to use it wisely.

Here is a brief explanation of each option:

  • Option a: The cement industry. Limestone is the main ingredient in cement, which is a binding agent that is used in concrete and other construction materials.
  • Option b: Construction. Limestone is used in a variety of construction materials, including concrete, bricks, and tiles.
  • Option c: Steel production. Limestone is a source of calcium, which is used in the production of steel.
  • Option d: Fertilizer manufacturing. Limestone is used to neutralize acidic soils.