In the Research Example That Evaluated the Effects of Subliminal

In the research example that evaluated the effects of subliminal self-help tapes on weight loss, which of the following was true?

A) the study used both a placebo control and a waiting list control
B) the study was a good example of the failure to use a proper control group
C) the tapes worked-participants using them lost weight, while those in the placebo group actually gained some weight
D) participants in the yoked control group listened to non-subliminal tapes