What advantage does a large, soft brush have over a small, stiff brush for a very thin watercolour wash?

Correct answer: It can hold more liquid and cover evenly with fewer strokes

The governing concept is brush capacity and softness in a watercolour wash. A large brush holds more diluted paint and releases it smoothly, while its soft bristles reduce pressure marks and streaks. This allows a broad area to be covered evenly with fewer interruptions. Therefore, option A is correct. A small stiff brush has lower capacity and may leave visible bands; it does not make paint opaque or limit the brush to dots.