A researcher wants to test whether participating in support groups will boost the immune system of people with AIDS. Her expectation is that participation will enhance immune functioning. For this purpose, she recruits a large pool of adults with AIDS and randomly assigns half to an hour-long support group that meets once a week for six months and half to a solitary activity of the same duration and frequency. The table below presents the data she collected after the 6-month intervention. A higher score indicates better immune functioning. The immune functioning of the two groups was the same prior to the intervention. She found that the critical value of the test statistic is 1.7 and the observed value of the test statistic is 1.5. All of the assumptions for the relevant statistical test to be valid were met. What should the researcher conclude? O Participating in a social support group degrades immune function 0 Participating in a social support group boosts immune function 0 Participating in a social support group has no effect on immune function 0 Having AIDS has an effect on immune function