What is the term for the removal of an unpleasant stimulus in response to a behavior?

The correct term for the removal of an unpleasant stimulus in response to a behavior is negative reinforcer. In behavioral psychology, a negative reinforcer refers to a stimulus that, when removed after a particular behavior, increases the likelihood of that behavior being repeated in the future. This is distinct from a punisher, which aims to decrease a behavior rather than encourage it.

For example, if a student studies to avoid the unpleasant feeling of anxiety before an exam, the removal of that anxiety reinforces the studying behavior. It's important to note that while negative reinforcement involves the removal of an unpleasant stimulus, it does not mean punishment; rather, it creates a more favorable condition following a desired behavior.