A Double-Blind Study Means __________

A double-blind study means __________.

A) the patient is unaware whether he or she is taking a placebo or the actual drug,though the doctor is aware of which drug was taken
B) the doctor is unaware whether the patient is taking a placebo or the actual drug,though the patient is aware of which drug was taken
C) both the doctor and the patient are unaware of whether a placebo or the actual drug was taken
D) only a limited number of staff know what the patient is taking