Why are the darkest values in glass usually not uniform across the whole form?

Correct answer: They concentrate in selected edges, reflections, and thicker areas

The governing concept is the observation of transparent materials through varied values. Glass does not have one uniform dark tone; its strongest darks usually appear where edges overlap, the material becomes visually thicker, or reflected surroundings create concentrated accents. These selected darks help describe transparency and form. Option A is correct. B contradicts observation, C ignores the glass itself, and D is false because pencil can represent glass through controlled values.