Question

which air pollutant most contributes to asthma?
emissions
contaminated groundwater
particulate matter
carbon monoxide

Explanation:

• "Emissions" is a general term for the release of pollutants, not a specific pollutant, so it's incorrect.
• "Contaminated groundwater" is a water - related contaminant, not an air pollutant, so it's incorrect.
• Particulate matter (PM) can be inhaled and irritate the airways, triggering or worsening asthma symptoms. It is a major air pollutant associated with asthma exacerbation.
• Carbon monoxide is more related to issues like reducing oxygen - carrying capacity in the blood rather than being a primary trigger for asthma.

Answer:

C. particulate matter