They built walls around their cities for protection
Explanation:
Sargon the Great
Around 2,300 BC, the independent city-states of Sumer were conquered by a man called Sargon the Great of Akkad, who had once ruled the city-state of Kish. Sargon was an Akkadian, a Semitic group of desert nomads who eventually settled in Mesopotamia just north of Sumer.
I'm sure the answers d, because it would help way more than the other options you'd want to know first hand what happen the only way to do so is to speak to those who fought in the war.