Bacterial decay produces methane from organic matter

Steps:

• Recognize bacterial decay as anaerobic decomposition of vegetable matter.
• Recall that methanogenic bacteria convert organic compounds to methane in low-oxygen environments.
• Match this to pollutant gases among options.
• Eliminate gases not primarily from this biological process.

Why B is correct:

• Methane (CH₄) forms via anaerobic respiration where bacteria break down cellulose in vegetable matter, releasing it as a greenhouse gas.

Why the others are wrong:

• A: Carbon monoxide arises from incomplete combustion of fuels, not bacterial decay.
• C: Nitrogen dioxide results from high-temperature combustion or atmospheric reactions, unrelated to vegetable decay.
• D: Sulphur dioxide emits from volcanic activity or fossil fuel burning, not organic decomposition.

Final answer: B