Answer:
Option: A. supplying water to fields with dams and canals.
Step-by-step explanation:
The Mesopotamia economy was based on agriculture. They focused on the cultivation of cereals (barley). Because of the harsh climate, the arid soil and little rain, there was a requirement for large scale irrigation through dams and canals. Canals built to bring the water for the fields to grow crops. Canal also divert water direction, which limits the damage from floods.