Answer: A) The Cuban Missile Crisis
Context/detail:
The Cuban Missile Crisis was a tense face-off between America, led by President John F. Kennedy and the Soviet Union, led by Nikita Khrushchev, in October of 1962, over the placement of Soviet missiles on the island of Cuba, close to the United States home territory. It is often stated that this moment was the closest the USA and the USSR ever came to the eruption of an actual nuclear war between the two superpowers.