To Test Their Theory of Emotion,Stanley Schachter and Jerome Singer

To test their theory of emotion,Stanley Schachter and Jerome Singer injected some participants with epinephrine and some with a placebo.If Schachter and Singer conducted a double-blind experiment,then:

A) no participant would know whether he or she had received epinephrine or a placebo,but the assistant administering the study would know whether a given participant had received epinephrine or a placebo.
B) each participant would know whether he or she had received epinephrine or a placebo,but the assistant administering the study would not know whether a given participant had received epinephrine or a placebo.
C) each participant would know whether he or she had received epinephrine or a placebo,and the assistant administering the study would also know whether a given participant had received epinephrine or a placebo.
D) no participant would know whether he or she had received epinephrine or a placebo,and the assistant administering the study would also not know whether a given participant had received epinephrine or a placebo.