Which condition is most suitable for creating texture with a dry brush in watercolour?

Correct answer: A lightly damp brush with relatively thick paint

Dry-brush texture depends on keeping moisture low so that the brush leaves broken, discontinuous marks instead of a smooth wash. A lightly damp brush carrying relatively thick paint catches the slight tooth of the paper and reveals its surface grain. Option D is correct. A wet brush, watery paint, or wet paper would cause pigment to flow continuously and would produce soft washes rather than the rough, broken texture required.