The fossil fuels include:
     A) Uranium
     B) Soil
     C) Natural gas
     D) Plants

Hint: Fossil fuels are fuels that are formed from fossils. Fossils are petrified remains of plants and animals that have been trapped in rocks. They have a lot of hydrocarbon content and therefore, can be used as fuel.

Complete step by step solution:
Fossil fuels are fuels that are formed from fossils. Fossils have a lot of hydrocarbon content, which can be burnt to produce energy, carbon dioxide and water vapor.
Fossils are the petrified remains of ancient plants and animals that have been somehow trapped in rocks.
Some examples of fossil fuels include petroleum, natural gas and coal.
Natural gas is a very common fossil fuel that is used in its compressed form, that is, Compressed Natural Gas (CNG). Compressed Natural Gas is used in vehicles as a fuel, since it is a very clean non-polluting fuel that does not produce toxic gases as by-products.
Hence, natural gas is a fossil fuel.
Therefore, the correct option is C) Natural gas.
Additional information:
Another common fossil fuel that is used in many domestic homes is liquefied petroleum gas (LPG). It is used as a cooking gas in domestic households.
Petrol and diesel are types of petroleum that are used as fuels for cars.

Note: Students might think that plants are also fossil fuels since fossil fuels are ultimately formed from remains of plants and animals. Hence, they may mark option D) Plants as the correct answer. However, that is not true since only remains of plants can become fossil fuels since the carbon content in the remains gets concentrated over many centuries to be viable enough to be used as a fuel. Hence, fossil fuels take centuries to form and their resources are getting depleted due to overuse. This is causing the energy crisis in the whole world.