Answer:
A) a baby
Step-by-step explanation:
John B. Watson was a psychologist wich helped develop behaviorism. He wanted to objectively study, by the use of experiments, the relations between environmental events and human behaviour. Together with Rosalic Rayner, he designed the "Little Albert" experiment, in this experiment he wanted to show that emotional reactions could be classically conditioned in people. They used a 9 months baby, "Albert B", they exposed him to a series of stimuli including a white rat, a white rabbit, a monkey, masks, and burning newspapers . At the beginning the boy didn't show fear, but then when Watson showed him the rat, a loud noise was made, making the boy cry. After doing this several times, the boy cried by just watching the rat. Watson conditioned "Little Albert"'s response to an specific stimulus.