The correct answer is: Cement.
Limestone is a sedimentary rock composed mainly of calcium carbonate (CaCO3). It is the most common sedimentary rock on Earth, and it is found in all continents. Limestone is formed when the remains of marine organisms, such as coral, algae, and shellfish, accumulate on the seafloor. Over time, these remains are buried and compacted, and they eventually turn into limestone.
Limestone is a valuable resource because it can be used to produce a variety of products, including cement, fertilizer, pharmaceuticals, and construction materials. Cement is a key ingredient in concrete, which is one of the most widely used building materials in the world. Fertilizer is used to improve crop yields, and pharmaceuticals are used to treat and prevent diseases. Construction materials, such as bricks and tiles, are used to build homes, offices, and other structures.
The limestone deposits in Manipur are significant for the production of cement. The state has a large reserve of limestone, and it is one of the major producers of cement in India. The cement industry in Manipur is a major contributor to the state’s economy, and it provides employment to thousands of people.
The other options are incorrect because limestone is not a major source of these materials. Fertilizer is made from a variety of materials, including phosphate rock, potash, and nitrogen. Pharmaceuticals are made from a variety of materials, including plants, animals, and minerals. Construction materials are made from a variety of materials, including wood, steel, and concrete.