What was the reason for superpowers to engage in an arms race with a strategy of mutually assured destruction? a. both countries felt that they were safe from attack if they were powerful enough to destroy the other. b. the united states expected a nuclear war at any moment and wanted to make certain it could win. c. the soviet union expected a nuclear war at any moment and wanted to make certain it could win. d. both countries felt that if they had nuclear weapons, no other countries would develop them.