Which natural resource is a fossil fuel?

Coal is classified as a fossil fuel because it is formed from the remains of ancient plants and animals that have been subjected to heat and pressure over millions of years. This transformation process is a defining characteristic of fossil fuels, which include coal, oil, and natural gas. Fossil fuels are primarily composed of carbon and are utilized extensively as energy sources for electricity, heating, and powering vehicles.

In contrast, water is not a fossil fuel; it is a renewable resource used for drinking, irrigation, and hydropower generation. "Wild" does not refer to a specific natural resource and seems to be an ambiguous choice. The sun represents solar energy, which is also a renewable resource, entirely distinct from fossil fuels. Understanding these distinctions highlights why coal is the correct answer in the context of fossil fuels.