What is a fossil fuel?

A fossil fuel is accurately defined as a natural fuel formed from the remains of living organisms, primarily plants and marine organisms, that have been buried and subjected to heat and pressure over millions of years. This process leads to the formation of coal, oil, and natural gas, which are classified as fossil fuels. These energy sources are non-renewable, meaning they cannot be replenished in a human timescale, making them significant in discussions about energy consumption and environmental impact.

The other options do not provide the correct definition of fossil fuels. Renewable sources of energy, such as hydropower, do not involve the decomposition of ancient organic materials and instead harness the energy from water flow. Biodegradable fuels, while derived from organic materials, are typically sourced from more recent plant material, rather than ancient remains. Solar energy is a distinct type of energy that is harvested from sunlight, and it does not encompass fossil fuels or natural gas. Thus, option B is the most accurate representation of what constitutes a fossil fuel.