Concept:Operant conditioning is a learning method where behavior is shaped by rewards or punishments.Explanation:This theory was developed by psychologist B.F. Skinner. Unlike classical conditioning (which pairs stimuli), operant conditioning focuses on voluntary actions. When a behavior is followed by reinforcement, it becomes more likely to repeat. When followed by punishment, it becomes less likely. Because the organism learns by “instrumentally” acting on the environment, operant conditioning is also called instrumental conditioning.Answer:D. Instrumental conditioning