What characterizes a delta?

A delta is specifically characterized as a low-lying landform created by the accumulation of sediment that a river carries and deposits as it flows into a larger body of water, such as an ocean, sea, or lake. This process occurs over time as the river slows down at its mouth, resulting in the deposition of silt, sand, and other materials. The buildup of these sediments forms the distinct shapes and features typical of deltas, such as their triangular or fan-shaped configurations.

The other options describe different geographical features. A high-altitude landform does not match the definition of a delta because deltas are low-lying areas. A steep riverbank may be indicative of erosional processes rather than the accumulation of sediments, which is crucial for delta formation. A freshwater lake is a body of water but does not describe the sedimentary processes involved in forming a delta. Therefore, option B is the accurate characterization of a delta.