Aversive conditioning is

the process by which a conditioned response can recur after a time delay.

the process of rewarding successive approximations of desired behavior.

the weakening of the conditioned response when the unconditioned stimulus is absent.

the form of treatment that consists of repeated pairings of a stimulus with a very unpleasant stimulus.

The correct definition of Aversive conditioning is the form of treatment that consists of repeated pairings of a stimulus with a very unpleasant stimulus.

Behaviorists researchers had applied techniques of aversive conditioning, also called aversive therapy for testing animal learning process, it requires the induction of some stimulus with something simultaneously unpleasant and this may lead the behavior to be stopped. This therapy can be used for nail biting, adding some unpleasant flavor in some product that goes into the nail, this may lead the person to stop biting her nails.