No, the answer is C. If it was A and the air cools, then why are deserts hot? The answer is C because as air rises it heats up and lose a its moisture through evaporation, leaving hot dry air for the deserts. This is called the rain shadow effect, where one side of the mountain is moist and cool and the other side is a desert.
Dead zones are hypoxic (low-oxygen) areas in the world's oceans and large lakes, caused by "excessive nutrient pollution from human activities coupled with other factors that deplete the oxygen required to support most marine life in bottom and near-bottom water.
Your answer would be, Letter (A), <span>Endemic diseases can result in decreasing population numbers: many people die from diseases, and others move away from or avoid moving to places where diseases are rampant.
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