What effect may result from placing concentrated colour on a damp surface?

Correct answer: A dark shape with controlled soft edges

The governing concept is the contrast between pigment concentration and surface moisture in wet-on-wet watercolour. Concentrated paint supplies a dark central deposit, while the damp paper allows water to carry some pigment outward and soften the boundary. The result can be a dark shape with controlled soft edges. A hard dry line requires a drier surface; white paper comes from leaving or lifting paint, and paint does not cut the surface, so A is correct.