What word or phrase provide a context clue to help determine the meaning of evidence

Prove, could perhaps be a word or another word to describe evidence...

Im pretty sure it’s is c

To solve their problems, mesopotamians used irrigation, a way of supplying water to an area of land. to irrigate their land, they dug out large storafe basins to hold water supplies these ditches brought water to the feilds. to protect their feilds from flooding, farmers built up the banks of the tigris and euphrates.hope ths !