Answer:
B. classical conditioning.
Explanation:
This example supports the idea that anxiety disorders may result from classical conditioning. Classical conditioning as described by Pavlov showed that a stimulus like food aroused an unconditional response of salivation in dogs. This response could be conditioned without the presence of the specific stimulus of food. In the case of the mice, anxiety-related behaviors are conditioned to arouse in Laboratory Room 20A without the presence of the electric shocks, because they have learned that their lives are threatened in that place.