Dr. graham exposes rats to a vanilla scent prior to receiving a food pellet in the left corner of their cage, but provides no food after exposure to a lemon scent. after several trials, upon smelling a vanilla scent, the rats wait at the far left corner of the cage regardless of whether a food pellet is present. however, they do not wait in the far left corner when exposed to the lemon scent. what is the unconditioned stimulus in the experiment?

Food pellet

Explanation:

A learning process which results due to an associated between two stimuli, one a natural stimulus and the other an environmental stimulus is known as classical conditioning. For classical conditioning, there is a neutral stimulus as well as the unconditioned stimulus. The unconditioned stimulus is the one which triggers a response in the organism automatically that is naturally without any prior learning.In the given example, the food pellet is the unconditioned stimulus.

Ibelieve the answer is d: quarterany