When a response is strengthened because it is followed by the presentation of a rewarding stimulus, it is called

A) punishment.
B) negative reinforcement.
C) positive reinforcement.
D) primary reinforcement.

Positive reinforcement occurs when a response is strengthened by the presentation of a rewarding stimulus. This is different from punishment, which is meant to decrease the likelihood of a certain behavior, and negative reinforcement, which occurs when a response is strengthened by the removal of an aversive stimulus. Primary reinforcement refers to a stimulus that is inherently rewarding, such as food or water, whereas positive reinforcement can involve both primary and secondary reinforcers (i.e. conditioned stimuli that become rewarding through association with primary reinforcers).