Select the correct answer.

Which of the following statements best explains why there tends to be a greater number of large cities in southern Africa than in East Africa?

A. East Africans are less traditional and thus less likely to westernize than southern Africans.
B. East Africans tend to prefer to work as merchants, while southern Africans tend to prefer to farm for a living.
C. Southern African cities are more expensive to live in than East African cities.
D. Southern Africa has a better climate and more industry than does East Africa.