Cichlid fish live in large lakes where they aggressively defend their territories against intruding males.
Sexually active male fish have brightly colored spots, while immature fish lack these spots.
In laboratory tests using models of various shapes, sizes, and colors, males attacked the spotted models, even when they were not fish- shaped.
They did not attack the fish-shaped models that lacked spots. These data suggest that
A. aggressive behavior is learned.
B. the spots represent an unconditioned response.
C. the spots cause a conditioned reflex.
D. the spots represent a fixed action pattern.
E. the spots are a releaser for aggressive behavior.