The primary source of smog-causing pollutants is
A) power plants.
B) automobiles.
C) charcoal grills.
D) airplanes.

Question

Quizplus · Accepted Answer

While all of these sources contribute to air pollution, automobiles are the primary source of smog-causing pollutants. This is particularly true in urban areas where there are high concentrations of cars on the road. Power plants and airplanes also contribute to air pollution, but to a lesser extent. Charcoal grills can emit pollutants, but are not a significant contributor to smog.

The Primary Source of Smog-Causing Pollutants Is