Answer:
Spontaneous recovery
Step-by-step explanation:
Spontaneous recovery is the reemergence of a response which was conditioned that had been erased. This happens as the person is not exposed to the Stimulus which was conditioned over a long period of time.
Here, Blain had not been exposed to the stimulus which was conditioned over a long period of time so the conditioned response was almost erased. But, when Blain was exposed to the Conditioned Stimulus his conditioned response came back. His conditioned response was being afraid of the geese.
Hence, this is an example of spontaneous recovery.