How are strokes applied in cross-brushing?

Correct answer: In one direction and then crossing it with another

The governing concept of cross-brushing is the intersection of separate stroke directions. The artist first lays marks one way and then applies another layer across them, producing a crossed texture and often a more blended or varied colour effect. Therefore option C is correct. One-direction marks are not cross-brushing, circular marks use a different movement, and a brush held away cannot create the intended surface marks.