______ is the use of value to create the illusion of depth.\na. shadowing\nc. modeling\nb…

Brief Explanations:

Shadowing uses value differences to give the appearance of depth by indicating light and dark areas on an object or in a scene. Foreshortening is about representing an object in perspective to make it look as if it recedes into the distance. Modeling is about creating a three - dimensional form. Sfumato is a technique for softening the transition between colors.

Answer:

a. Shadowing