Answer:
The correct answer is C. Neutral stimulus: knock on the door; CS: knock on the door; UCS: cocaine.
Step-by-step explanation:
According to Pavlov, an individual can acquire a certain behavior by relating it to various stimulus.
- At first, the knock on the door is considered a neutral stimulus, since it does not trigger any certain response.
- The cocaine is an unconditioned stimulus since at first it only generates Alexis's shakiness and heart pound.
- Once the neutral stimulus mixes with the unconditioned stimulus, the neutral stimulus (knocking on the door) becomes a conditioned stimulus since it will make Alexis nervous as she is expecting the dealer.