The correct answer is D) A direct telephone hotline between Washignton and Moscow.
The Cuban Missile Crisis was the closest the world has ever come to seeing all out nuclear warfarea. After the US discovered several Soviet Union missiles in Cuba (only 90 miles of the coast of Florida), the US called for the immediate removal of the missiles. After initial refusal by the Soviet Union, the US implemented a quarantine of Cuba in order to prevent more weapons from being brought in. This seemed like an aggressive act to the leader of the Soviet Union, causing tensions to rise. Ultimate, the situation was solved in a peaceful manner. However, the development of a direct telephone line between Washington and Moscow became a staple. This was created in hopes of preventing increased tensions and increased communication between the leaders of the aforementioned countries.