According to the NYT article, what is the most typical "winning strategy" for a repeated prisoner's dilemma game?

Group of answer choices

a. tit-for-tat

b. always defect-- this works like nuclear deterrence to make your opponentbelieve you are a credible threat

c. always cooperate-- this is a "nice" strategy and it will encourage your opponent to cooperate as well

d. cooperate, then during the last round, defect