The correct answer is: D) Lignite
Lignite is a type of coal that is found in Kerala. It is a soft, brown coal that is formed from plant material that has been buried and subjected to heat and pressure over millions of years. Lignite is used to generate electricity, produce steel, and make chemicals.
Iron ore is a mineral that is used to make iron and steel. It is found in rocks and minerals, and it is mined in open-pit or underground mines. Iron ore is a major export of Kerala.
Bauxite is a mineral that is used to make aluminum. It is found in rocks and minerals, and it is mined in open-pit or underground mines. Bauxite is not a major export of Kerala.
Ilmenite is a mineral that is used to make titanium dioxide. It is found in rocks and minerals, and it is mined in open-pit or underground mines. Ilmenite is not a major export of Kerala.