The best criterion for evaluating this piece of art, which features a cartoon drawing with the phrase "free your mind" inscribed where the brain would be located, would be:
use of color to emphasize a particular area of the drawing
This is because the phrase is directly tied to the visual representation of the brain, and color can play a significant role in drawing attention to this crucial aspect of the artwork. The other criteria, while valuable in other contexts, would not align as closely with the thematic elements and intended message of this specific piece.