The correct option is A Anthracite
Coal is formed when the organic material is buried under sediment and is subjected to high temperature and high pressure for millions of years. The formation of coal takes place in four stages: peat, lignite, bituminous and anthracite coal. As the coal formation proceeds, the product is increasingly characterized by the low moisture content, high carbon content and hardness. Anthracite has the highest carbon content. It has about 87% of carbon content and is often referred to as hard coal for this reason.