What made the climate of northern Africa change from tropical to grasslands, and then to desert?

tilt of the earth's axis
the Nile River
Ice Ages
overpopulation of the region

Question

What made the climate of northern Africa change from tropical to grasslands, and then to desert?

tilt of the earth's axis
the Nile River
Ice Ages
overpopulation of the region

paki · Answer

what you think about the answer here...?

anonymous · Answer

i was going to say B?

anonymous · Answer

The Nile is in Egypt. Not Africa. .w.

anonymous · Answer

no

paki · Answer

not B... choose between A and C...

anonymous · Answer

i was going to say A, but i second guessed myself.

paki · Answer

agree with A " The first is the change in the tilt of the Earth which put more direct sunlight onto Northern Africa. "

anonymous · Answer

As my old science teacher would say " The reason for the season is the tilt"

anonymous · Answer

*Throws confetti* Good job!

paki · Answer

@fierstar123 nice:)