According to Study Findings, What Kind(s) of Contact Will Make

According to study findings, what kind(s) of contact will make behavioral programs successful to help people stop smoking?​

A) ​Face-to-face contact is required for counseling to be effective.
B) ​Computer/web-based contact is more effective than in-person.
C) ​Text messaging is found less effective than web-based contact.
D) ​Smokers can quit and avoid relapse through all these methods.