Correct Answer:
C. Methane and Carbon Dioxide
The correct answer is Methane and Carbon Dioxide. Biogas is produced by the anaerobic decomposition of organic matter. It is primarily composed of methane (CH₄) (typically 50‑70%) and carbon dioxide (CO₂) (30‑40%), along with small amounts of other gases. Among the options:
- Ethane and Oxygen: Not a biogas composition.
- Propane and Carbon Monoxide: Not typical of biogas.
- Methane and Carbon Dioxide: Correct; these are the main components of biogas.
- Butane and Nitrogen: Not a biogas composition.
Hence, the correct answer is "Methane and Carbon Dioxide".