Answer: The correct answer is-
C. Crude oil is found below natural gas reservoirs.
Crude oil is a unrefined form of petroleum. Natural gas and crude oil both are nonrenewable sources of energy that are formed by remains of plants and animals that died millions of years back.
Natural gas is lighter as compared to crude oil. So natural gas has lower density as compared to crude oil. Due to this, crude oil is found below the natural gas reservoirs.
Thus, option C) is the right answer.