How should the brush be when removing a paint bead from the bottom of a wash?

Correct answer: Damp and clean

The governing concept is controlled lifting. A clean, damp brush has enough absorbency to pick up the excess paint bead without introducing a new flood of water or pigment. Therefore option D is correct; the brush should usually be lightly blotted first. A dripping brush spreads the wash, a dry brush lifts poorly, and a paint-loaded brush adds colour.