Which of the Following Strategies Would Be Most Successful in Producing

Which of the following strategies would be most successful in producing cooperation in a prisoner's dilemma game?

A) Make competitive choices on each trial, regardless of what choice your opponent makes.
B) Make cooperative choices on each trial, regardless of what choice your opponent makes.
C) First make a competitive choice, and thereafter make the opposite response that your partner made on the prior trial.
D) First make a cooperative choice, and thereafter make the same response that your partner made on the prior trial.