During president nixon's presidency the Cold War entered a 'detente' phase, which is best described as

A) reduced tensions with the Soviet Union and signed treaties to limit nuclear weapons.

Explanation:

When Nixon was President, the US and Soviet Union signed the Strategic Arms Limitation Treaty (aka SALT) in 1972. This treaty specifically limited the amount of long-range missiles available to both countries as well as the amount of balistic missiles with nuclear weapons. This period of detente significantly decreased the probability of nuclear war between these two countries.