Burt Witnesses a Mugging on a Crowded Bus,but Does Nothing

Burt witnesses a mugging on a crowded bus,but does nothing to help the victim.When later asked by the police to explain his inaction,Burt says that he figured someone else would help the victim.Burt has cited which explanation for the bystander effect?

A) arousal-cost-reward
B) diffusion of responsibility
C) group inhibition
D) social contagion