The Cuban Missile Crisis, which unfolded in October 1962, was a critical moment during the Cold War, bringing the world to the brink of nuclear conflict. It involved a tense standoff over the deployment of Soviet nuclear missiles in Cuba.
The correct answer is US & Soviet Union. This confrontation was primarily a direct struggle between the two global superpowers: the United States, led by President John F. Kennedy, and the Soviet Union, led by Premier Nikita Khrushchev. Cuba was the focal point, but the principal adversaries were these two nations.
Canada, Russia is incorrect; Canada was not a primary party, and the conflict involved the Soviet Union, not modern-day Russia. US, Canada & Cuba is also incorrect because while Cuba was central to the crisis's location and stakes, the direct confrontation and negotiation were between the US and the USSR, not involving Canada as a primary combatant.