The Participants in Philip Zimbardo's Simulated Prison Study

The participants in Philip Zimbardo's simulated prison study

A) were assigned the roles of prisoner or guard on the basis of their personality test scores.
B) found it very difficult to play the role of prison guard.
C) were so endangered by their role-playing experience that the study was
Discontinued.
D) became a cohesive unit when they pursued superordinate goals.