Which of the Following Best Explains the Bystander Effect

Which of the following best explains the bystander effect?

A) It is an occurrence that describes how individuals in a group can act together without planned direction.
B) It is an effect that causes people to ignore matters that are generally important to a group but may not seem specifically important to the individual.
C) It is a phenomenon in which the more people who witness an emergency, the less likely any one of them will help.
D) It is abusive treatment, the use of force or coercion to affect others, particularly when habitual and involving an imbalance of power.