In a graded wash uneven bands appear instead of a smooth light-to-dark transition. What should be corrected first?

Correct answer: Change paint concentration gradually and join edges while damp

The governing concept of a graded wash is a controlled change in pigment concentration supported by smooth timing between adjacent strokes. Starting with a lighter mixture and gradually increasing pigment creates the tonal transition; joining edges while they are still damp prevents visible bands. Option A is correct. Drying every band creates hard divisions, a harder brush cannot solve the tonal problem, and one dark colour removes the required gradation.