Is the Lack of a US Revaluation Effect in Taste

Multiple Choice

Is the lack of a US revaluation effect in taste aversion good evidence that the animals may not be learning to expect the US in this paradigm?

A) Yes, changes in the US should affect changes in the response elicited by the CS.
B) No, we do not fully understand the situations in which US revaluation will produce clear changes in responses.
C) Yes, US revaluation effects are easy to see in virtually all other paradigms.
D) No, taste aversion is a form of S-S learning in which such effects are not always expected.