Which cue is most useful for clarifying the volume of a glossy black object?

Correct answer: Selected light reflections and sharp edge changes

The governing concept is the interaction of reflected light, material, and form. A glossy black surface has a dark local value, but its sharp highlights and controlled changes at curved edges reveal how the surface turns in space. These selected reflections communicate both volume and gloss, so option A is correct. Uniform blackness hides form, a thick contour describes only the boundary, and excessive softness removes the useful value contrast.