In a multi-period prisoners' dilemma, the Republican and Democratic parties have two strategies available to them: run attack ads or run friendly ads. If they both run attack ads, they will each get $7 million in donations from their support bases. If one party runs attack ads and the other runs friendly ads, then the party who runs attack ads will get $13 million and the party who runs friendly ads will get $6 million. If, however, both run friendly ads they will each get $11 million. There is no definite end to the interaction between them. Assume that the Democrats play the Tit-for-Tat contingent strategy. For what values of r (the rate of return on an investment) will it be worthwhile for the Republican party to run attack ads once against the Democratic party? A) > 0.03 B) > 0.5 C) > 1.5 D) > 2 E) > 2.5