Answer:
I believe your answer should be a.
cars and phones made modern city life possible
The correct answer is that what led the Soviet Union to establish the Warsaw Pact was that West Germany joined NATO in 1955.
The Treaty of Friendship, Cooperation and Mutual Assistance, better known as the Warsaw Pact, was a military cooperation agreement signed on May 14, 1955 by the countries of the Eastern Bloc. Designed under the leadership of the Union of Soviet Socialist Republics (USSR), its express purpose was to counteract the threat of the North Atlantic Treaty Organization (NATO), and in particular the rearmament of the German Federal Republic, to which the Paris Agreements allowed to reorganize their armed forces and join the NATO. The Pact was dissolved on July 1, 1991.
