Answer:
Aversive conditioning
Explanation:
Aversion conditioning is the conditioning process that is used to avoid undesired behavior. The stimuli are associated with the noxious stimulus or undesired stimulus to avoid undesired behavior or response. This is a therapy that is used to reduce the behavior that is undesirable for all.
Thus Paul gets an injection to avoid excessive smoking. This injection is given because Paul can avoid that undesirable behavior that is not accepted in the society.
This conditioning is useful in another disorder such as OCD.