Which of the following describes the placebo effect?
o
a. at least one block of subjects in an experiment receives only
placebos.
o
b. subjects may respond to a treatment simply because they believe
it is affecting them.
c. subjects receive inactive sugar pills instead of real medication.
o
d. an experiment is repeated many times with real drugs and
placebos
o
e. subjects are prevented from knowing whether they are receiving
real drugs or placebos.