President Nixon and Secretary of State Kissinger successfully pressured the Soviet Union into making diplomatic deals with the US by
a. playing the China card by opening US diplomacy and trade with the Soviets' rival communist power
b. using American economic aid as an incentive for the Soviets
c. threatening to attack Soviet allies such as Cuba and Vietnam
d. drastically increasing spending on nuclear weapons and missiles
e. building an anti-ballistic missile system that effectively neutralized the Soviet nuclear threat