Which of the Following Statements About the Prisoner's Dilemma Is

Which of the following statements about the prisoner's dilemma is false?

A) The prisoner's dilemma in a one-shot game leads to a noncooperative, equilibrium outcome.
B) The prisoner's dilemma in repeated games could lead to cooperation especially if there is some enforcement mechanism that punishes a player who does not cooperate.
C) Players caught in a prisoner's dilemma act in selfish ways that lead to an equilibrium that is sub-optimal.
D) The prisoner's dilemma game can never reach a Nash equilibrium as long as players do not cooperate.