Final answer:
In operant conditioning, unlike classical conditioning, no specific stimulus produces a particular response. Instead, the behavior is influenced by the consequences that follow, making the association voluntary and reinforcing the likelihood of the behavior being repeated.
Step-by-step explanation:
The distinction between classical conditioning and operant conditioning lies in the association and responses to stimuli. In classical conditioning, like the renowned experiments by Ivan Pavlov, an unconditioned stimulus such as food is paired with a neutral stimulus like a bell, which eventually becomes the conditioned stimulus prompting a conditioned response such as salivation.
Conversely, operant conditioning, as illustrated by B.F. Skinner's work, involves an active behavior that is strengthened or weakened by its consequences, a process used in most animal training. A behavior (e.g., pressing a lever) is followed by a consequence (e.g., receiving food), which reinforces the likelihood of that behavior being repeated.
Therefore, regarding the specificity of the stimulus in operant conditioning, the correct answer to the question is D. No specific stimulus produces a particular response. Instead, the response in operant conditioning is shaped by the consequences that follow the behavior, leading to a voluntary association between the behavior and its outcomes, rather than a specific stimulus causing a reflexive response as in classical conditioning.