In Milgram's Research on Obedience

In Milgram's research on obedience

A) participants thought they were shocking someone else, although they really weren't.
B) participants did not think they were administering shock to someone else, although they actually were.
C) the "learner" was a real participant, while the "teacher" was a confederate of the experimenter.
D) teachers who refused to shock learners were threatened with shock themselves.