Which method is most suitable for keeping a flat watercolour wash even?

Correct answer: Sufficient mixture and continuous even strokes

The governing concept of a flat wash is maintaining a consistent supply of similarly diluted colour across the area. Prepare enough mixture before beginning, keep the paper positioned appropriately, and work with continuous, overlapping strokes while the edge remains workable. A is correct because it reduces visible bands and interruptions. Changing water with every stroke is impractical, a very dry brush produces patchiness, and folding the paper cannot create an even wash.