Which method is useful if a filled colour layer looks uneven?

Correct answer: Apply light, even strokes before it dries

The governing concept is achieving an even colour layer through timely, consistent brushwork. If the paint is still moist, light strokes in one direction can redistribute it and reduce streaks or patches before the layer sets. Thus, option A is correct. Hard scraping may tear the paper or remove paint, adding unrelated colours makes the surface less uniform, and folding can crack or damage the painted sheet. The artist should work gently and avoid repeatedly disturbing a nearly dry layer.