Answer:
Even though you didn't post the answer choices, we can safely say that the conditioned response is feeling nauseated at the sight of the fudge counter.
Explanation:
A conditioned response is a learned behavior triggered by a conditioned stimulus. In other words, a conditioned response is not a natural, automatic response to something, but a response learned because of something that has happened previously.
To Gino, feeling nauseated is an unconditioned response to peanuts. That means it is an automatic response, one that happens naturally as a result of his allergy. At first, fudge is a neutral stimulus, since it does not trigger any automatic response in Gino. However, as soon as he eats the fudge that has peanuts in it, Gino becomes nauseated. Now, his brain has associated the fudge with the nausea. The sight of fudge has become, therefore, a conditioned stimulus that triggers a conditioned response - feeling nauseated.
Simply put, before eating the fudge with peanuts:
Unconditioned stimulus - peanuts
unconditioned response - feeling nauseated
neutral stimulus - fudge
After eating the fudge with peanuts:
conditioned stimulus - fudge
conditioned response - feeling nauseated at the sight of fudge