What is a key characteristic of concave landforms?

Concave landforms are primarily characterized by having a depression or low point. This means that the land surface curves inward, resembling a bowl or an inverted surface where elevation decreases toward the center. This distinctive shape allows for water accumulation in these areas, contributing to the formation of features such as valleys or basins.

In contrast, other choices refer to features that are not typical of concave landforms. For example, a high point or ridge describes elevated areas, while a linear high ground would imply a consistently raised terrain. An open plain generally denotes a flat and expansive area that does not exhibit the inward curvature characteristic of concave landforms. Therefore, focusing on the defining feature of concave landforms, which is the presence of a depression or low point, illustrates why this choice is correct.