What are "fossil fuels" primarily composed of?

Fossil fuels are primarily composed of the remains of ancient plants and animals that lived millions of years ago. Over long periods of time, these organic materials underwent geological processes such as heat and pressure, transforming them into coal, oil, and natural gas. This biological origin is crucial in understanding the formation of fossil fuels, as they are essentially stored solar energy, derived from the sunlight that was captured by living organisms through photosynthesis in previous geological eras.

In contrast to the other options, natural minerals from the Earth are not the source of fossil fuels; they refer instead to inorganic materials found naturally in the environment. Renewable energy sources, such as solar or wind, do not involve ancient biological remains and are quite distinct from fossil fuels, which are finite and take millions of years to form. Current organic material, such as living organisms, is not directly involved in the creation of fossil fuels as they are already processed and transformed into fossil fuels through the long-term geological changes mentioned.