Which class of map projection is designed to maintain scale?

The correct classification of a map projection designed to maintain scale is equidistant. Equidistant projections are specifically designed to ensure that distances measured on the map are accurate for certain lines or from a specific point. This characteristic allows users to accurately measure distances between locations on the projected map without distortion.

In contrast, conformal projections maintain angles and shapes of small areas, which is ideal for navigational purposes but may distort distances. Equivalent projections focus on maintaining area proportions, ensuring that the area of land on the map is represented according to its true size, but this does not guarantee that distances are preserved. Azimuthal projections can show true directions from a central point, but they may not maintain uniform scale over larger areas.

This context highlights why equidistant is the appropriate choice when the focus is on maintaining scale.