Answer:
C.the fighting among city-states
Step-by-step explanation:
Sumer was conquered through military domination by different semitic people. Sumer was made up of city states .the states were independent nations. Due to political power, rivalry grew between these city states.
Then there were their neighbors the Akkadian empire. This empire had military strength and we're known for conquest. They were responsible for Ur's destruction and the Sumerian language was replaced by Akkadian.