The correct answer is B) reduced tensions with the Soviet Union.
SALT is an acronym that stands for Strategic Arms Limitation Talks. These talks between the United States and Soviet Union resulted in certain limits put on military capabilities by both countries in order to ease tensions during the Cold War. These talks were helpful in bringing on a period of detente (reduced tension) between the two sides. These treaties arouse after the 1960's, in which the United States and Soviet Union were mere minutes away from all out nuclear warfare during the Cuban Missile Crisis.
Separation of powers is a political doctrine originating in the writings of Charles de Secondat, Baron de Montesquieu in The Spirit of the Laws, in which he argued for a constitutional government with three separate branches, each of which would have defined abilities to check the powers of the others.