Telling her that she will never be able to stop smoking will slowly kill her confidence and she will slowly go back into doing it. Scolding her for sneaking a cigarette will more likely make her want to do it more because you're constantly telling her no. Celebrating her and worshipping her will make her feel better, and make her more willing to stop smoking.
The answer is B. A does not make sense because Jessica should encourage her friend not discourage her. C is also incorrect because when you often scold at someone about something they will probably do the exact opposite of what your telling them to do.
