Edwin Happens Upon a Crime in Progress but Does Nothing

Edwin happens upon a crime in progress but does nothing to assist the victims or even summon the police. Later, he says he was afraid for his personal safety. This type of explanation, which may help explain the inaction of witnesses in the case of Kitty Genovese, is best described by the principle of _________.

A) perceived cost.
B) situational ambiguity.
C) diffusion of responsibility.
D) attributions of the cause of need.
E) cognitive dissonance.