What best describes a drumlin?

A drumlin is best described as a long mound of till that has been shaped and smoothed in the direction of glacial movement. This landform is typically formed by the accumulation of glacial debris and sediment, known as till, which is moved and reshaped by the flow of the glacier. The long, tapered shape of a drumlin indicates the direction in which the glacier was advancing, with the steeper end facing the direction of flow and the gentle slope leading away from it.

In contrast, a ridge left at the end of a glacier refers to a terminal moraine, which marks the furthest advance of the glacier, rather than an elongated structure. A flat area covered with eolian sediments describes a completely different landform, such as a desert or dune landscape influenced by wind, and is not associated with glacial activity. A steep valley formed by water erosion would be more indicative of river or stream processes and does not relate to the formation of drumlins, which are strictly tied to glacial processes.