The cement industry in Tamil Nadu relies heavily on the availability of:

Iron Ore
Gypsum
Limestone
Bauxite

The correct answer is c) Limestone.

Limestone is the main raw material used in the manufacture of cement. It is used to make clinker, which is then ground with gypsum to make cement. Limestone is a sedimentary rock that is formed from the accumulation of calcium carbonate. It is found in many parts of the world, including Tamil Nadu.

Iron ore is a mineral that is used to make steel. It is not a major raw material in the manufacture of cement.

Gypsum is a mineral that is used to regulate the setting time of cement. It is also used to make plasterboard and other building materials.

Bauxite is a mineral that is used to make aluminum. It is not a major raw material in the manufacture of cement.

Here is a brief explanation of each option:

  • Iron ore is a mineral that is used to make steel. It is a major raw material in the manufacture of steel, but it is not a major raw material in the manufacture of cement.
  • Gypsum is a mineral that is used to regulate the setting time of cement. It is also used to make plasterboard and other building materials. Gypsum is not a major raw material in the manufacture of cement, but it is an important ingredient.
  • Limestone is the main raw material used in the manufacture of cement. It is used to make clinker, which is then ground with gypsum to make cement. Limestone is a sedimentary rock that is formed from the accumulation of calcium carbonate. It is found in many parts of the world, including Tamil Nadu.
  • Bauxite is a mineral that is used to make aluminum. It is not a major raw material in the manufacture of cement.