A naturally occurring hydrocarbon that consists mostly of methane.

• A. Oil
• B. Biomass
• C. Natural Gas
• D. Renewable Resource

Answer: (C)

When a hydrocarbon occurs naturally and is dominated by methane, the substance is natural gas. Methane is the simplest hydrocarbon (one carbon atom with four hydrogens), and natural gas is mainly methane, often with smaller amounts of other gases. It forms underground from ancient organic matter under heat and pressure and is tapped for heating, electricity, and cooking.

Oil is a liquid hydrocarbon, not primarily methane. Biomass refers to organic material, not a hydrocarbon gas. A renewable resource describes energy sources that replenish quickly, not a specific naturally occurring hydrocarbon. Therefore, natural gas is the correct choice.