The most abundant fossil fuel is
a. natural gas
c. coal
b. oil
d. all of the above

c. coal

Explanation:

Fossil fuels consist of deposits of fossil organisms that were once alive. Organic matter is formed for centuries. Fossil fuels consist mainly of carbon and hydrogen bonds. There are three types of fossil fuels that can be used for energy provision: coal, oil and natural gas. Coal is a fossil fuel that has been formed for millions of years by the deposit and fall to the ground of plant material. When these layers are compacted and heated over time, the deposits are transformed into coal. Coal is very abundant compared to other fossil fuels. Analysts sometimes predict that worldwide the use of coal will increase when there is a shortage of oil. Current coal supplies can last on the order of 200 years or more. Coal is usually extracted from mines. Since the mid-20th century, the use of coal has doubled. Since 1996 its application begins to decline. Many countries depend on coal as an energy source because they cannot afford to use oil or natural gas because it is more expensive.