When the material A mined from the earth ,is heated strongly in an insufficeint supply of air, it produces a solid fuel B which consists mainly of carbon. When another material C obtained from trees is heated in an insufficient supply of air, it produces another solid fuel D which also consists mainly of carbon. Name A, B, C and D.

A is coal; It is mainly made up of 65-95% carbon and also contains hydrogen, sulphur, oxygen and nitrogen.

B is coke; Coke is a fuel with few impurities and a high carbon content, usually made from coal.

C is wood;

D is charcoal; Charcoal is a lightweight, black residue, consisting of carbon and any remaining ash, obtained by removing water and other volatile constituents from animal and vegetation substances.