Which of the following best explains the bystander effect?
a. 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.
b. it is an occurrence that describes how individuals in a group can act together without planned direction.
c. it is abusive treatment, the use of force or coercion to affect others, particularly when habitual and involving an imbalance of power.
d. it is a phenomenon in which the more people who witness an emergency, the less likely any one of them will .

It is a phenomenon in which the more people who witness an emergency, the less likely any one of them will help is the statement that best explains the bystander effect.

The bystander effect explains the psychological phenomenon by which a person becomes immobilized when witnessing an emergency situation where they would be expected to provide support to someone in significant danger.

Therefore, we can conclude that the bystander effect is your term used in psychology for the phenomenon in which when the person becomes part of a crowd, the less likely it is that a person in distress will receive help.

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im 100% sure its all of the above.