The correct answer is: a) Lignite.
Lignite is the lowest rank of coal, and is the most abundant type of coal found in Meghalaya. It is a soft, brown coal that is formed from plant material that has been buried and subjected to heat and pressure for millions of years. Lignite is used primarily for generating electricity and for producing coke, which is used in the steelmaking industry.
Bituminous coal is a higher rank of coal than lignite, and is black in color. It is formed from plant material that has been buried and subjected to heat and pressure for longer than lignite. Bituminous coal is used primarily for generating electricity, for producing coke, and for making chemicals.
Anthracite is the highest rank of coal, and is black and shiny. It is formed from plant material that has been buried and subjected to heat and pressure for the longest period of time. Anthracite is used primarily for generating electricity and for making chemicals.
Peat is a type of organic soil that is formed from partially decomposed plant material. It is not a true coal, but is sometimes referred to as “brown coal”. Peat is used primarily for fuel, for making fertilizer, and for landscaping.