What should be checked between pencil grades when progressing from hard to soft?

Correct answer: The value range and pressure condition on the paper

The governing concept is controlled value building. Moving from a hard grade to a softer one should be based on the darkness already achieved and on whether the paper surface still has enough tooth. Checking the value range and pressure condition, as stated in option A, prevents sudden dark patches and burnishing. Pencil length, contour thickness alone, and paper price do not determine whether the next shading grade is appropriate.