Many Americans Complain About Being Sleep Deprived

Many Americans complain about being sleep deprived. A team of psychologists researched the reasons for this sleep deprivation. After determining that one reason was poor time management, they devised a program to help people manage their time better. They recruited a random sample of 30 people at a major shopping center and randomly split them into three groups of size 10. Group 1 (the controls) received a logbook asking them to record the number of hours slept for a week but nothing else. Group 2 (the informed group) was shown a video to help improve time management. Group 3 (the intervention) participated in a two-day training course on improving time management. Groups 2 and 3 were also asked to keep records for one week on the number of hours slept. The psychologists were interested in learning if providing information or an intervention affects sleep time. Below are 95% Tukey simultaneous confidence intervals for the pairwise comparisons of all three pairs of means. Based on these results, which of the following statements is true?

A) Clearly, all three means are the same, since all confidence intervals include zero or nearly do so.
B) We can be 95% confident that the intervention mean is different from both the control mean and the information mean, and the control mean and the intervention mean are not different.
C) We can be sure that the intervention group is different from the control and information groups, and the information group is not different from the control group.
D) We can be confident that the intervention mean is different from the control mean and information mean, while the control mean and information mean are not different, but we do not know the confidence level.