What type of sediment might be found on top of a lake plain?

The correct answer, indicating that alluvium or glacial sediment might be found on top of a lake plain, is valid because lake plains are typically formed from the deposition of sediments in a lake environment. These sediments can be influenced by various geological processes.

Alluvium refers to sediment that has been deposited by flowing water, often found in river valleys and floodplains. In certain cases, when rivers flow into a lake, they can deposit alluvial sediments along their deltas or where they enter the lake, contributing to the sediment profile on the lake plain.

Additionally, glacial sediment consists of materials that have been transported and deposited by glacial activity, which can also accumulate on a lake plain, particularly if glaciers have shaped the landscape surrounding the lake or if they have released sediments during melting events.

While other options, such as lacustrine sediment and eolian deposits, represent sediment types associated with certain environments, they do not encompass the broader range of sediments that might be found in conjunction with or on top of a lake plain. Organic sediment primarily involves decomposed plant material and may not dominate in the same way as alluvial or glacial sediments in a lake plain setting. Thus, the presence of alluvium and glacial