While filling a narrow shape, the centre colour is even but paint spreads beyond the edges. What is the most suitable correction?

Correct answer: Use a small pointed brush with less paint and light pressure near the edges

The governing concept is matching brush size and paint load to the space being filled. A small pointed brush, a reduced amount of paint, and light pressure give precise control near a narrow boundary; the centre can then be filled carefully. Option C is correct. More water or a large fast brush would increase spreading, while erasing the boundary removes the guide instead of solving the technique problem.