The Milgram obedience experiments were controversial because the

A) "teachers" actually seemed to enjoy shocking the "learners."
B) "learners" received painful electric shocks even if they had heart problems.
C) experiments were performed despite mass student protests against the research.
D) "teachers" were deceived and frequently subjected to stress.

The Milgram obedience experiments were controversial because the "teachers" in the study were deceived and frequently subjected to stress, which many argued was unethical treatment of the participants. While it is true that some "teachers" appeared to show enjoyment in shocking the "learners," this was not the main source of controversy. The use of electric shocks on participants with heart problems did occur, but this was not a widespread issue in the experiments. There were no mass student protests against the research that were significant enough to halt or significantly alter the experiments.