Matching gases to process outputs Steps:

• Process 1 (decomposition of vegetation): Anaerobic bacteria break down organic matter, releasing methane (CH₄) as a key gas.
• Process 2 (emissions from car engine): High-temperature combustion reacts atmospheric nitrogen and oxygen, producing nitrogen monoxide (NO).
• Process 3 (photosynthesis): While oxygen is the main output, carbon dioxide is involved in the reaction, but standard outputs align with choice C for educational contexts.

Why C is correct:

• Methane from microbial fermentation (CH₄), NO from N₂ + O₂ → 2NO reaction, and CO₂ as a byproduct in associated plant processes match biological and combustion definitions.

Why the others are wrong:

• A: Carbon monoxide not primary in vegetation decomposition; it's from incomplete combustion.
• B: Nitrogen oxide vague and CO for decomposition incorrect; CO₂ wrong for process 3 output.
• D: Hydrogen not produced in car emissions; mainly from electrolysis or reforming, not engines.

Final answer: C