Medical Experiments, Such as One to Compare Aspirin with a Placebo

Multiple Choice

Medical experiments, such as one to compare aspirin with a placebo for preventing heart attacks, are often double-blind. This means that

A) neither the subject nor the doctors know which treatment the patient received.
B) subjects choose which treatment they get, but do not tell the doctors.
C) the doctors choose which treatment to give each subject, but do not tell the subjects.
D) subjects are not told either their treatment or their medical condition.
E) all individual data are kept confidential.