Glen is attempting to use operant conditioning to train his dog, thor, to fetch a ball upon command. at the beginning of the training, glen throws the ball and yells “fetch,” but thor only watches glen expectantly. which of the following is the most likely reason to explain why thor does not fetch the ball? a. fetching is a behavior that thor is not intelligent enough to comprehend. b. fetching is a complex behavior that has not been shaped by glen. c. fetching is simple behavior, but thor is generalizing the stimuli. d. fetching is a behavior that glen must demonstrate to thor by example.