Carol and Martin are participating in the Prisoner's Dilemma, where each is promised a certain amount of money for either cooperating or defecting. If Carol and Martin are married and their goal is to win the highest possible combined total of money, what should they each do?

The best thing for them to do is to cooperate.

Explanation:

In the Prisoner's dilemma game, cooperation would mean that the both parties are giving equal share of an amount. However, if they betray each other, the amount of money that will be given will be smaller, and if one betray the other, and the other remains silence, only one person will be rewarded. Hence cooperation is always the best option with the greatest reward in the Prisoner's dilemma game.