What are the branches of the main river in a delta called?

Correct answer: Distributaries

The direct answer is C, Distributaries. A delta forms near the mouth of a river when the river slows down and divides into several smaller channels. These channels carry the river water and deposited sediment toward the sea or lake. A tributary is different: it joins a main river and adds water to it, rather than branching away from it. A water divide is a high land boundary separating two drainage basins; it is not a river branch. A distributary leaves or branches away from the main river, so option C is correct. A waterfall is a sudden vertical fall of water, usually over a steep rock step, and has no special meaning as a delta branch. Remember: tributaries join a river, while distributaries leave a river, especially near its mouth.