Answer: Self reference
Step-by-step explanation:
Self reference effect is the effect in which information is encoded by people in various ways. Recalling rate is improved through this process has recollection of information is done through personally encoded information.
According to the question, self reference effect is implemented in this situation as smoking habit related activities are recollected and related so that it can make Barbara remember that she should avoid such event which triggers smoking need in her.She can focus on stress reduction technique instead.