In the Mock Prison Study Carried Out by Zimbardo and Colleagues

In the mock prison study carried out by Zimbardo and colleagues:

A) norms developed over the course of the study that led to cooperation between prisoner and guard
B) guards became more and more abusive over the course of the study
C) prisoners did not take the situation seriously, but the guards certainly did
D) the study was supposed to last one week, but was extended to three weeks
E) both c and d