In a crowded mall parking lot, dozens of people hear a female voice yell, "He's killing me!" Yet no one calls the police. What is the reason for the lack of action, according to Darley and Latané?

a) People are too busy to respond.
b) Most people "do not want to become involved."
c) The fight-or-flight response is not activated when others are in danger.
d) Diffusion of responsibility is the reason most people do not respond.

d