Which of the following statements about contour lines is true?

Contour lines are a crucial element in topographic mapping, serving to represent elevation changes across a landscape. The correct statement, that contour lines connect points of equal elevation, highlights their primary function. By connecting these points, contour lines provide a visual representation of the terrain's shape—showing where the ground rises and falls. This allows for a clear interpretation of the topography, helping readers understand the gradient and steepness of slopes.

The other options do not accurately describe the function of contour lines. While some features of the terrain are indicated by the configuration of contour lines, such as hills and valleys, they are not limited to just the highest points, nor do they exclusively represent flat terrain or mark water bodies directly. Instead, contour lines can depict a range of elevations, including flat areas, slopes, and depressions, making them essential tools for understanding the relief of a given area.