C. The Mesopotamians used a series of crisscrossing channels.
Mesopotamians developed an intricate system of irrigation that included a network of canals and channels to manage and distribute water from the rivers, primarily the Tigris and Euphrates, to their fields. This system allowed them to cope with the irregular flooding and drought conditions of the region. In contrast, Egyptians primarily used basin irrigation, which involved capturing floodwaters from the Nile in basins to irrigate their crops.