In 1971, Phillip Zimbardo and Colleagues Conducted an Experiment to Learn

In 1971, Phillip Zimbardo and colleagues conducted an experiment to learn about the power of roles. The subjects were randomly assigned to a "prisoner" group or a "guard" group. The guards were to do whatever they deemed necessary to maintain control. Less than two days into the experiment, one prisoner had a "nervous breakdown." Because the experimenters believed that the prisoner was trying to trick them into releasing him, they laughed at him for being weak and made him stay. If this experiment were done today, it would be in violation of the APA's ethical standards for informed consent, because

A) studies are not permitted to last for multiple days
B) it is unethical to study prison situations
C) the researchers lied about what they were studying
D) the study would be ethical if it were done today
E) the participant was not allowed to leave freely without penalty