Answer:
A. Cold War
Step-by-step explanation:
The reason I choose this answer is because both world powers were at each others throat's because of many reasons: 1. They both wanted to spread their believe and eliminate the other one(Communism vs. Capitalism). 2. They both wanted to create the strongest nuclear weapon. 3. They both wanted to get to space(the moon) first. 4. They both had set up missiles very close to each others country(The US set up missiles in Turkey and the USSR set up missiles in Cuba). 5. They both wanted to become the strongest world power.
All of these facts lead up to the fact that the USSR might have killed Kennedy to slow down the US while the USSR gained more power and time to complete their goals.