Question

what are the most common air pollutants?
a. hydrogen, nitrogen, cyanide.
b. carbon monoxide, sulfur dioxide, and nitrogen.
c. ozone, carbon monoxide, and sulfur dioxide.
d. ozone, carbon dioxide, and hydrogen.

Explanation:

Ozone (in the troposphere), carbon monoxide, and sulfur dioxide are well - known air pollutants. Hydrogen is not a common air pollutant. Nitrogen is a major component of air (about 78%) and not a pollutant in its elemental form in normal concentrations. Carbon dioxide is a greenhouse gas but not typically considered one of the most common "air pollutants" in the same category as the others in the context of criteria pollutants (ozone, CO, SO₂).

Answer:

C. Ozone, carbon monoxide, and sulfur dioxide.