Final answer:
Stationary sources of air pollution are not an example of nonpoint source pollution.
Step-by-step explanation:
Nonpoint source pollution is contamination that results from the buildup of small amounts of contaminants that collect from a large area. Examples of this include fertilizer runoff from agricultural fields, oil and antifreeze from urban areas, and acid and toxic elements from abandoned mines.
The correct answer is stationary sources of air pollution. Stationary sources, such as factories and power plants, are considered point sources because they emit pollutants from a single location.