How should brush strokes be used for even colour filling?

Correct answer: Slightly overlapping

The governing concept is continuous, even coverage. Slightly overlapping brush strokes close small gaps between passes and distribute the paint more uniformly, producing a consistent surface. Therefore, option C is correct. Strokes placed far apart leave unpainted spaces, random directions can create uneven texture, and working only along the edges cannot fill the entire shape. Consistent pressure and direction also help maintain an even result.