For which effect is a dry brush used in watercolour?

Correct answer: Rough texture

The governing concept is that a dry brush carries little water and leaves broken marks across the paper’s tooth. Those irregular marks reveal the surface and are useful for rough textures such as wood, dry grass, or stone, so option A is correct. An even wash needs a wetter, controlled brush, while wetting paper requires clean water. Very soft clouds are usually developed with softer wet techniques rather than a strongly broken dry-brush mark.