Final answer:
Fossil fuels such as oil, coal, and natural gas were produced over millions of years from decomposed organic matter under high pressures and temperatures. The specific types of fossil fuels formed depend on the original organic material and environmental conditions during decomposition. These fuels are trapped beneath dense rock formations from where they are extracted. The correct option is A.
Step-by-step explanation:
Fossil fuels originate from the organic matter of plants, algae, and cyanobacteria that have been buried and then subjected to high temperatures and pressures over millions of years. These conditions lead to the fossilization process, transforming this biomass into various forms of fuels such as oil, coal, and natural gas.
The conditions that contribute to the formation of each type of fossil fuel can vary - oil and natural gas generally come from organisms that lived in aquatic environments and were buried under sediments, while coal primarily originates from plants that were buried under swampy areas. Over time, layers of soil and rock put pressure on these dead organisms, and in an anaerobic environment with high heat, they slowly decompose and transform into fossil fuels.
The specific type of fossil fuel formed - whether natural gas, oil, or coal - depends on what organic material was present, the length of time it was buried, and the temperature and pressure conditions at the time. Once these substances were formed, they often migrated and became trapped beneath dense rock formations known as 'caprocks', which is where we usually find and extract them today.
Hence, Option A is correct.