Negative reinforcement is best defined as:

Negative reinforcement is a concept in behavioral psychology that involves increasing the likelihood of a behavior by stopping or reducing an aversive stimulus. This occurs when a behavior leads to the removal or avoidance of something unpleasant, thereby reinforcing that behavior.

In the definition provided, when a negative stimulus is present and is removed as a result of a specific behavior, it encourages that behavior to occur more frequently in the future. For instance, if a child is allowed to leave a noisy environment by completing their homework, the act of completing their homework is reinforced because it leads to the cessation of the unpleasant noise.

Understanding negative reinforcement helps practitioners create supportive environments for individuals with autism, where desired behaviors are encouraged by the elimination of uncomfortable or aversive conditions, fostering a more positive learning experience.