A major reason why people won't help when there are many bystanders is because:

A) of diffusion of responsibility.
B) people are egoistic.
C) people like to see others hurt.
D) people are not altruistic.

Bystanders

Individuals who are present at an event or incident but do not take part.

Diffusion of Responsibility

A sociopsychological phenomenon where individuals are less likely to take action or feel a sense of responsibility in the presence of a large group of people.