Answer:
d. spontaneous recovery.
Explanation:
As a child, Blaine was attacked by a goose and subsequently developed a severe fear of waterfowl. As he got older, the fear gradually faded until it was all but forgotten. Blaine is now in his early-twenties and recently went strolling through a park by the river where he came across a flock of geese. The geese gave him a start and he felt slightly fearful, though not as afraid as he had been as a child. Blaine's fear response is an example of spontaneous recovery.
Spontaneous recovery in learning and conditioning is the reappearance of a conditioned response that has been extinguished due to an exposure to the conditioned stimulus after a long period of time.
The feeling of fear is a conditioned response by Blaine when attacked by geese, however, with time that response extinguished but on exposure to geese recently, that conditioned response was spontaneously recovered.