Answer:
a. moved east and south.
Step-by-step explanation:
What is today the arid, hot and inhospitable Sahara desert, in North Africa, was a region of savannas and leafy meadows with some forests and the home of hunters and gatherers who lived from a variety of animals and plants, supported by lakes permanent and large amounts of rainfall.
A study in which Dr. Pausata of the University of Stockholm participated analyzed past rainfall and concluded that human hunters and gatherers who populated the green Sahara abandoned it about 8,000 years ago due to a drought period that lasted 1,000 years.