Which brush is useful for making fine lines?

Correct answer: Thin pointed brush

The governing technique is using a narrow, controlled tip for detailed marks. A thin pointed brush holds a small amount of colour and allows the artist to guide the tip accurately, making it suitable for fine lines; therefore, option B is correct. A broad flat brush covers larger areas, while a sponge and cloth are not designed to produce precise painted lines. The brush should not be overloaded, because excess colour can form drops and make a line uneven.