In general, no, Mesopotamia did not fall because of attack from other empires, since it was primarily due to the Tigris and Euphrates Rivers drying up that led to a lack of produce, and therefore a fall in the empire itself.
Answer:
Hello there! Elizabeth here! I would choose either B:the Mediterranean Sea & D:Nile River. But if your answer only required 1 answer, then I would 100% choose C. Nile River, or else wise the Egypt civilization wouldn't be able to server their 'Boss', or to be able to survive by not eating the wheat bread.
<em>I hope this helped you! I'm so sorry if my answer is incorrect!</em>
<em>Have a good day/night!</em>
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<em>^~Elizabeth</em>
Supposition is not a mode of historiographer disclosure