Which option defines positive punishment?

• A. Introducing an unpleasant stimulus to decrease a behavior
• B. Removing a pleasant stimulus to decrease a behavior
• C. Introducing a pleasant stimulus to increase a behavior
• D. Removing an unpleasant stimulus to increase a behavior

Answer: (A)

In operant conditioning, positive punishment means adding an aversive consequence after a behavior to reduce how often that behavior occurs. The option that describes introducing an unpleasant stimulus to decrease a behavior fits this exactly. The other options correspond to different principles: removing a pleasant stimulus to decrease a behavior is negative punishment; introducing a pleasant stimulus to increase a behavior is positive reinforcement; removing an unpleasant stimulus to increase a behavior is negative reinforcement.