Answer:
conditioned stimulus; conditioned response
Explanation:
In respondent conditioning, also known as classical conditioning, a natural potent stimulus (food) that elicits a response naturally is paired with a neutral stimulus (bell), which initially would not produce any response but only attract attention. Learning or new behavior is elicited in this way.
The previously neutral stimulus which now elicits salivation is referred to as conditioned stimulus, while the salivation is called the conditioned response.