Texture

The governing concept is that texture must support the form and its light-and-shadow structure. Texture marks should follow the surface direction and become lighter, darker, clearer, or less visible according to the light source. If light direction is ignored, the marks may look pasted onto the object instead of belonging to its surface, making the drawing unrealistic. Proportion, paper size, and background do not change for this reason, so option D is correct.

The governing concept is surface texture and pigment granulation. Some relatively heavy or large pigment particles remain unevenly dispersed in water and settle into the tiny hollows of textured paper. As the wash dries, the particles collect in those depressions and create a speckled, grainy appearance, so option A is correct. Uniform dissolution produces a smoother wash, while water does not turn paint white and a normal brush does not cut the paper.

The governing concept is texture observation and directional mark-making. Wood has visible grain that generally travels along a lengthwise direction, so long, slightly uneven strokes following that grain create a convincing linear texture. Option A is correct. Random dots, uniform thick bands, or no marks do not describe the directional variation of wood.

The governing concept is texture matching: brushwork should communicate the surface quality of the object. A rough rock is better represented with broken, irregular strokes and uneven colour variation, while a smooth vessel needs connected blending and controlled transitions that suggest a continuous surface. Identical strokes ignore the difference, black alone cannot show texture, and reversing the techniques contradicts the objects’ surfaces. Therefore, option A is correct.