Which of the Following Statements Is True

Which of the following statements is true?

A) Temperature inversions occur when a layer of cold air prevents warm air from rising.
B) Temperature inversions exacerbate pollution problems.
C) Temperature inversions last only a few minutes to a few hours.
D) Normally, cool air near Earth's surface expands and rises, carrying pollutants higher into the troposphere.
E) Temperature inversions help prevent air pollution.