The Essence of a Prisoner's Dilemma Setting Is That If

The essence of a prisoner's dilemma setting is that if both person A and person B do what is best for each of them,

A) they end up in a position that is "the best" for each of them.
B) they end up in a position that is "the worst" for each of them.
C) one ends up in a position that is "the best" for him and the other ends in a position that is "the worst" for him.
D) they end up in a position from which each would prefer to move away.