The correct option is C Anthracite, bituminous, lignite, peat.
The time variation of the coalification process, as well as the depth at which the coal is found, affects important properties of coal. Anthracite is a grade of coal that has undergone coalification more than peat and is found in the deeper layers of the earth. This is why it has the maximum carbon content, least moisture and on burning, the energy released is more and almost smokeless compared to the burning of peat which releases a lot of fumes in addition to the low energy released.
PropertyPeatLigniteBituminousAnthraciteMoistureHighestHighRelatively lowerLowestHardnessSoftestSofterSoftHardestUpon burningSmokeSmokeSmokeSmokelessCarbon content<40%<40%40−90%>90%