Which of These Does NOT Contribute to Africa's Frequent Droughts

Multiple Choice

Which of these does NOT contribute to Africa's frequent droughts?

A) Much farming is done on marginal lands subject to long cycles of frequent droughts.
B) Only about 10 percent of Africa's land is arable.
C) Overpopulation is a continent-wide problem.
D) The tropical rainforest is rapidly diminishing due to the need for lumber to export.
E) Leaders have recently been concentrating on the development of family farms.