What characterizes a delta?

A delta is characterized by its formation at the point where a river meets a larger body of water, such as an ocean or a lake. In this setting, the river's flow slows down upon entering the larger body of water, leading to the deposition of sediment that the river has carried with it. Over time, this sediment builds up and creates a landform known as a delta, often resulting in a triangular or fan-shaped appearance. This process plays a crucial role in the ecology of the area, as deltas provide rich habitats for wildlife and fertile ground for agriculture due to the nutrient-rich sediment deposited by the river.

The other choices refer to different geographical features. A narrow body of water is known as a strait or channel, which connects two larger bodies of water. An elevated landform created by volcanic activity describes a volcano or a mountain rather than a delta. Lastly, a flat area of land that is lower than the surrounding areas is typically referred to as a plain or a basin, which does not convey the specific sedimentary processes that define a delta.