Smoking cessation programs teach skills proven to help smokers quit and provide social support to reinforce non-smoking behaviors. Researchers have found that smokers who are enrolled in smoking cessation programs that include monthly support groups are more likely to successfully quit smoking than those who are not enrolled in a program. The researchers concluded that social support is critical to helping smokers successfully quit smoking. Which of the following statements, if true, would most seriously WEAKEN the above argument?
1) Smokers in weekly support groups are twice as likely to quit smoking as those in monthly support groups.
2) Smokers who are enrolled in cessation programs but do not participate in support groups are less likely to quit smoking.
3) Using the skills proven to help smokers quit, in addition to monthly support groups, increases the likelihood of smoking cessation.
4) Smokers using cessation medications have the highest success rate, regardless of participation in smoking cessation programs.
5) Attending a single support group session provides the same chance of quitting smoking as not attending any support group sessions.