1-84After Being Bitten by a Dog,Jose Finds That He Feels

1-84.After being bitten by a dog,Jose finds that he feels afraid whenever he sees a dog.He goes for treatment,where he is gradually exposed to dogs,until he can be in the same room with a dog without feeling any fear.Three weeks later,while walking in his neighborhood,Jose hears a dog barking viciously.For a few weeks after this,his fear returns.This shows

A) the treatment had no effect.
B) extinction.
C) stimulus-stimulus expectancy.
D) spontaneous recovery.