Taste-aversion research showed that when rats get sick after sampling a new food, they learn to avoid certain tastes but not the sights or sounds connected to the place they became sick. This finding supports the idea that
a. animals learn to react to similar stimuli in similar ways.
b. conditioning has survival value by helping animals adapt to their environment.
c. psychologists should only study observable behavior.
d. organisms can be conditioned to any stimulus.