What is the energy source of coal derived from?

The correct answer is based on the process of photosynthesis, where plants use sunlight to produce energy. Over millions of years, dead plant material, primarily from lush forested regions, becomes buried under sediment and subjected to heat and pressure, transforming it into coal. This process effectively locks away the energy originally captured from sunlight in the chemical bonds of hydrocarbons found in coal.

While the other options refer to different energy sources, they do not relate directly to the formation of coal. Fossilized marine life typically contributes to the formation of oil and natural gas rather than coal. Geothermal activity involves heat from within the Earth, which is not related to the energy stored in coal. Nuclear reactions occurring in the Earth's core pertain to processes happening at a subatomic level and do not contribute to the formation of coal or its energy content.