Final answer:
John Watson could have used extinction, presenting the rat without the loud noise repeatedly, to eliminate Little Albert's conditioned fear.
Step-by-step explanation:
To eliminate Little Albert's conditioned fear, John Watson could have used the process known as extinction, where the conditioned stimulus (CS) is presented without the unconditioned stimulus (UCS) repeatedly until the conditioned response (CR) diminishes. Therefore, the correct answer to what could have been done to eliminate Little Albert's conditioned fear is B. Show Albert a rat many times without a loud noise following. This is because Little Albert had been conditioned to fear the white rat (CS) by associating it with the loud noise (UCS) that naturally elicited a fear response (UCR). By presenting the rat without following it with the loud noise over multiple trials, the association would weaken, and his fear response (CR) to the rat would likely decrease or be extinguished over time. This approach is based on the principles of classical conditioning, first demonstrated by Ivan Pavlov and applied in Watson's experiment on Little Albert.