What is the most likely cause if a smooth line appears instead of a dry-brush texture?

Correct answer: The brush contained too much moisture or paint

Dry-brush texture depends on a nearly dry brush carrying only a small amount of paint. When the brush contains excessive moisture or paint, its bristles release colour continuously instead of leaving broken marks on raised areas, so a smooth line results. Option B identifies the most likely cause. A rough surface generally helps reveal broken texture, and brush size alone does not explain the loss of the effect.