Use the Following to Answer Questions

Use the following to answer questions
Scenario I
Scenario I is based on and presents fabricated data consistent with the following study:
Merikle,P.M. ,& Skanes,H.E.(1992) .Subliminal self-help audiotapes: A search for placebo effects.Journal of Applied Psychology,77(5) ,772-776.doi:10.1037/0021-9010.77.5.772
Merikle and Skanes (1992) investigated the effectiveness of subliminal self-help audiotapes to promote weight loss in overweight females seeking to lose weight.Participants were randomly assigned to groups.Participants in two groups were instructed to listen to audiotapes containing subliminal messages associated with weight loss daily.Group 1 (the subliminal group) actually received these tapes.Group 2 (the placebo group) received tapes containing subliminal messages associated with relieving dental anxiety.Finally,a third group of participants was not given audiotapes and was told that they were on a waiting list to participate in the study.All participants-including the participants on the waiting list-were weighed weekly for 5 weeks.The average total weight loss (and standard deviations) for the three groups after the fifth week is presented in Figure 5.1.
Figure 5.1
-(Scenario I) Suppose that Merikle and Skanes (1992) had studied ONLY the subliminal and placebo groups.Based on these data,what is the MOST reasonable conclusion?

A) The subliminal messages were effective at facilitating weight loss.
B) The observed weight loss in both groups is simply due to natural regression.
C) The subliminal messages might be effective at facilitating weight loss,but a waiting-list control group is needed to know for sure.
D) The observed weight loss in the subliminal group could be due to a placebo effect.