In Drug Studies,using a Double-Blind Experiment Design Ensures That

In drug studies,using a double-blind experiment design ensures that

A) the experimenter cannot make subtle gestures signaling who is receiving a drug and who is not.
B) the confederate always gets the placebo.
C) participants of the experiment are influenced by how they think they are supposed to behave or by their expectations about what is happening to them.
D) confounds are more apparent than demand characteristics or experimenter bias.