It is well known that model of prisoner’s dilemma explains why the states escape from cooperation. Therefore, while the realist approach based on prisoner’s dilemma emphasizes that possible risks and uncertainties might cause to escape/refrain from cooperation, free rider approach also argues that the existence of some countries trying to employ the collective action without paying any cost might restrict the cooperation of states.

Realists who are adopting the assumptions of uncertainty and prisoner’s dilemma assume that these mutual suspicion and non-confidence of states would feed and sustain the process. Therefore, international regimes would eliminate these uncertainties and feed the confidence instead of non-confidence.

Moreover, conditioned cooperation (if game is reiterated, players would be encouraged to cooperate in order to escape from the probable cost) in the model of prisoner’s dilemma might be effective to encourage states to establish regimes. Meetings frequently done between states to boost the cooperation would be main imperative for realization of conditioned cooperation in prisoner’s dilemma.

The correct answer is C.