Bart Developed a Fear of Flying When He Was Piloting

Multiple Choice

Bart developed a fear of flying when he was piloting a small plane through some severe turbulence. He has been seeing a therapist, and it appears that his fear response has been successfully extinguished. The therapist used a flight simulator to help Bart practice his piloting skills in a safe setting. However, the first time Bart stepped back into a real plane, his fear returned. This example illustrates the phenomenon known as

A) second-order conditioning.
B) the renewal effect.
C) unblocking.
D) stimulus generalization.