The study described in the question refers to the Stanford Prison Experiment, conducted in 1971 by psychologist Philip Zimbardo at Stanford University. This experiment was designed to examine the psychological effects of perceived power, authority, and institutional roles on human behavior.
In the experiment, college students were randomly assigned the roles of prisoners and guards within a simulated prison environment set up in the university basement. Despite careful screening to ensure participants were mentally healthy, the situation quickly escalated.
Participants began to internalize their assigned roles. Guards exhibited abusive, authoritarian behavior, while prisoners showed signs of extreme stress, emotional distress, and helplessness. These dramatic changes occurred not because of individual personality traits, but due to the situational pressures and power dynamics embedded in the institutional setting.
The experiment was terminated early due to ethical concerns, and it has since become a landmark study in psychology. It is frequently cited in discussions on abuse of power, institutional accountability, ethics in research, and the impact of social roles on behavior.
The other options listed involve different psychological studies—obedience to authority (Milgram), intergroup conflict (Robbers Cave), and social learning (Bobo Doll)—but none match the simulated prison context described in the question.
Hence, the correct answer is:
\(\boxed{(b)\ \text{The Stanford Prison Experiment}}\)