Which of the following is an example of a natural source of air pollution? A. Mining releases gases trapped beneath Earth's surface. B. Burning coal and natural gas releases carbon dioxide. C. Erupting volcanoes release many toxic gases. D. Plowing and harvesting crops releases dust particles.

The correct answer is (C) Erupting volcanoes release many toxic gases.

Air pollutants are gases that harms the environment and human health. Some air pollutants come from volcanic eruption are toxic (like sulphuric acid) and harm our health. Volcanic eruption produce soot and ash into the atmosphere, which reduces sunlight and lowers temperatures. Eruption also produce carbon dioxide, carbon monoxide and other polluting gases

Some other examples of natural air pollutants are:

1. Radon is a radioactive gas that seeps from the ground in some areas, and fog and mist are both dense water vapor at ground level that obscures vision. 2. Ozone, a chemical formed naturally by the action of sunlight on oxygen, is a pollutant at ground level but beneficial in the upper atmosphere. It damages plants and causes breathing problem in the lower atmosphere.

C. erupting volcanoes release many toxic gasses.