As a Result of Climatic Change in the Central Sahara

As a result of climatic change in the central Sahara during the second millennium B.C.E.,

A) large populations migrated there to take advantage of the fertile soil.
B) the native populations were wiped out by a series of ecological disasters.
C) new farming techniques were developed to accommodate the increase in rainfall.
D) populations left the increasingly arid region for more hospitable territory.