Question

Sierra lives in a southwestern town in a valley where air pollutants sometimes settle. The mountains that surround the town keep air pollution from blowing away. Sometimes Sierra can actually see the pollution in the air. Which choice is NOT a source of outdoor air pollution? A. Car emissions B. Factory emissions C. Radon gas D. Volcanic eruptions

Answer 1

C. would be the answer.

Step-by-step explanation:

Radon gas is a major indoor pollutant, not outdoor. The rest of the choices can cause outdoor air pollution.