Most Deserts Occur at Approximately 30° Latitudes

Multiple Choice

Most deserts occur at approximately 30° latitudes. Which of the following statements BEST reflects this finding?

A) Cool dry air descends at 30° latitude.
B) Warm dry air descends at 30° latitude.
C) Trade winds pull all moisture away from land and to the ocean at 30° latitude.
D) Westerlies pull all moisture away from land and to the ocean at 30° latitude.