Cathryn Conducted an Experiment That Involved Administering an Anti-Anxiety Drug

Cathryn conducted an experiment that involved administering an anti-anxiety drug to people with a history of Generalized Anxiety Disorder.Participants received 0 mg,50 mg,or 100 mg of the drug.Which participants received a placebo?

A) The 50 mg condition
B) The 100 mg condition
C) The 0 mg condition
D) There was no placebo