Best answer for Kennedy Administration would be
d) flexible response
"Detente" was really not used in foreign policy until the Nixon administration.
The Kennedy Administration's emphasis on "flexible response," which was officially called Flexible Detrrent Options, was to respond to the Soviet Union and other adversaries in ways appropriate to each situation. Flexible response meant using conventional weapons and diplomacy and other methods, not just relying on nuclear weapons and massive retaliation.
It was perhaps not so much a policy of "peaceful coexistence" as maintaining an existence that maintained peace as much as possible and pursued military actions in limited ways.
