Nitrogen oxides are emitted from high temperature combustion reactions. nitrogen oxides are an example of
a. primary pollutants
b. secondary pollutants
c. tertiary pollutants
d. none of the above

Nitrogen oxides are an example of secondary pollutants. :)

The correct answer in this question is option B. Nitrogen oxides are an example of secondary pollutants. A secondary pollutant when emitted directly is not harmful. When it combines with other pollutants, it will lead to damage in the environment such as acid rain.