Answer: Incomplete combustion in vehicle engines and industrial processes.
- 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 O<sub>2</sub>, causing asphyxiation.
Sunlight passes through the atmosphere and warms the surface; the surface re-radiates this energy as infrared heat, which greenhouse gases (CO₂, CH₄, water vapour) absorb and trap - a naturally beneficial process that intensifies into global warming as gas concentrations rise from human activity.
Concept context
Pollution, global warming, ozone depletion, deforestation, and sustainability. Important for NEET and general awareness.