Aperson eats a hamburger at a restaurant and develops a very bad stomachache after finishing eating. as a result of the sudden illness, the person cannot eat hamburgers anymore. just thinking about them makes the person feel sick to the stomach. in this scenario, the thought of a hamburger is:
a) unconditioned stimulus
b) conditioned stimulus
c) conditioned response
d) negative reinforcer

Conditioned stimulus

Explanation:

In the classical conditioned, these terms such as condition stimulus, UCS, CS, NS, etc are being used to modify the behavior of a person, animal, etc. The conditioned stimulus is neutral before as a conditioned stimulus. Ivan Pavlov was the first psychologist who has been used classical conditioning in which a person used CS, UCS, UCR, and CR.  

Thus here in the above statement, the person eats a hamburger. Before used it, it was a neutral stimulus but after using it, it becomes a conditioned stimulus.

in what process is there a multiple choice answer?