What is the best correction if clear bands appear in a graded wash?

Correct answer: Add intermediate tones to gradually blend the bands

Clear bands appear when adjacent values change too abruptly or when one wash stroke dries before the next connects with it. The sound correction is to introduce intermediate tones and blend them gently, preferably while the edge is still workable, so the value steps become gradual. Adding black increases contrast, rubbing a dry sheet damages the surface, and folding the paper cannot create controlled blending. Thus, option D is correct.