Final answer:
In Pavlov's classical conditioning experiment, food is the unconditioned stimulus, salivation to the food is the unconditioned response, the bell becomes the conditioned stimulus, the salivation to the bell sound is the conditioned response, and the bell before conditioning represents the neutral stimulus.
Step-by-step explanation:
In Pavlov's classical conditioning experiment, the items can be matched as follows. The food in the mouth, which naturally triggers salivation, is the (1) Unconditioned Stimulus (D). The response to the food, which is salivation, is known as the (2) Unconditioned Response (C). As conditioning continues, the previously neutral bell becomes associated with the food and is perceived as the (3) Conditioned Stimulus (E). The salivation which occurs in response to hearing the bell is now referred to as the (4) Conditioned Response (B). Lastly, the bell, which was a neutral factor before the experiment began, can be referred to as the (5) Neutral Stimulus (A).
Learn more about Pavlov's classical conditioning