Which row shows a substance found in clean air and a substance that acts as an air pollutant?
- Apresent in clean air: oxides of nitrogen; pollutant in air: nitrogen
- Bpresent in clean air: carbon dioxide; pollutant in air: sulfur dioxide
- Cpresent in clean air: carbon monoxide; pollutant in air: lead compounds
- Dpresent in clean air: nitrogen; pollutant in air: argon