What distinguishes a form from a shape?

• A. A form is flat.
• B. A shape has volume.
• C. A form appears to be three-dimensional.
• D. A shape is three-dimensional.

Answer: (C)

The difference being tested is depth and volume in visual elements. A shape is a flat, 2D outline with only height and width. A form suggests depth and mass, either as a real three-dimensional object or as a 2D depiction that looks three-dimensional through shading, light, and perspective. That’s why the best choice says a form appears to be three-dimensional: it conveys depth, making it feel like it occupies space. The other statements misfit because a form isn’t inherently flat, shapes don’t have volume, and a shape isn’t inherently three-dimensional.