From the window of his house, Dean sees a stranger fall off his bicycle on the sidewalk. Dean knows everybody in his community and can say definitively that this stranger is not from his neighborhood. He decides to go outside in the sweltering heat to help the man anyway, receiving nothing in return. In considering indirect reciprocity, why might Dean have acted in this way?
A) Dean's neighbours may have been watching.
B) The stranger looks similar to Dean's best friend.
C) Dean understands the notion of direct reciprocity.
D) The stranger looks like Dean's old roommate.
Anaswer: A