- A Emissions released from coal-fired power plant chimneys
- B Incomplete combustion in vehicle engines and industrial processes
- C Sulfur dioxide and ash released during volcanic eruptions
- D Ammonia released from fertilizer use in agricultural activities
Correct answer: B. Incomplete combustion in vehicle engines and industrial processes
Explanation: CO is produced by incomplete combustion of carbon-containing fuels. Main sources: motor vehicle exhaust (most significant in urban areas), industrial furnaces, burning wood/charcoal. CO is colourless, odourless, toxic - binds haemoglobin 250x more strongly than O2, causing asphyxiation.
Concept context
Pollution, global warming, ozone depletion, deforestation, and sustainability. Important for NEET and general awareness.