Final answer:
Fossil fuels such as coal, oil, and natural gas are named as such because they are derived from the ancient remains of prehistoric plants and animals, transformed into energy sources under intense pressure and heat over geological time.
Step-by-step explanation:
Coal, oil, and natural gas are called fossil fuels because they are derived from the ancient remains of plants and animals that lived hundreds of millions of years ago. When these organisms died, they were buried under layers of sediment and subjected to intense pressure and heat over millions of years. This process transformed their biomass into the different forms of fossil fuels: coal, petroleum, and natural gas. The term "fossil fuels" refers to the origin of these fuels as the preserved remains or "fossils" of ancient life and their subsequent conversion into sources of energy.