Wildfires are a. a human source of air pollution b. a natural source of air pollution c. both a natural and human source of air pollution d. none of the above

c. both a natural and human source of air pollution

Wildfires are important abiotic factor of the environment. These can be originated from natural or man-induced sources. The natural wildfire sources are volcanic eruptions, lightening during a thunderstorm and other ways. The man- induced sources includes the use of fuels to set up intentional fire to obtain a hold over the large forest land. This results in air pollution.

The answer is letter c.  It can be both natural and human source of pollution.  There are times when the intense heat can trigger a brush fire and can expand depending on how strong the wind blows.  It can be caused by humans.  it could due to carelessness of people leaving flammable materials unchecked. Or using too much fuel that when lit would cause a brush fire that would expand into a wildfires.  The smoke from it pollutes the air.