Which best describes the characteristics of a river basin?
A. the land drained by a river and its tributaries
B. the land formed when rivers create estuaries and marshes
C. the land at the mouth of a river where water flows into the ocean
D. the land formed as a result of a river flooding

The land drained by a river and its tributaries best describes the characteristics of a river basin.

Explanation:

A river basin also termed as drainage basin, water basin, catchment basin, or a watershed refers to the land which receives all the water and has been drained by the water from the river along with its tributaries. It is the collection center of water collected by the confluence all the natural water resources in that area.

The surface of the land in a river basin gets dissected by the flow of water from the tributaries, streams, and even small creeks of the rivers downhill or from other parts.

As the water flows, it brings in sediments rich in nutrients and also pollutants which gets settled in the river basin.

River basins are essential part of natural ecosystem and should be managed well for maintaining the water sources.