Which method is most suitable for blending two colours on wet paper without a hard edge?

Correct answer: Wet-on-wet

The wet-on-wet method applies watercolour to a damp surface, allowing neighbouring pigments to move into one another and form a soft transition. Option A is correct because the moisture reduces a sharp boundary when the two colours meet. Wet-on-dry generally creates clearer edges, while dry brush leaves broken texture and scratching removes or disturbs paint rather than blending it smoothly.