The correct option is A Bio
Biogas is primarily methane (CH4) and carbon dioxide (CO2) and may have small amounts of hydrogen sulphide (H2S), moisture and siloxanes.
Biogas typically refers to a mixture of different gases produced by the breakdown of organic matter in the absence of oxygen by anaerobic digestion with methanogen or anaerobic organisms, which digest material inside a closed system, or fermentation of biodegradable materials.Biogas can be produced from raw materials such as agricultural waste, manure,plant material,green waste or food waste. Biogas is a renewable energy source.