Which statement is true about discriminative stimuli (SDs)?

• A. They signal reinforcement is available for a response
• B. They indicate punishment will follow
• C. They have no effect on behavior
• D. They always cause the behavior automatically

Answer: (A)

Discriminative stimuli are cues that set the occasion for a behavior by signaling that reinforcement is available for that behavior. When this cue is present, the target response is more likely to occur because the reinforcement contingency is in effect. This explains why the statement that they signal reinforcement is available is correct. They do not indicate punishment, and they do not automatically evoke the behavior—the organism must still emit the response to obtain reinforcement.