The correct answer is D. North Atlantic Treaty Organization
Step-by-step explanation:
The NATO or North Atlantic Treaty Organization was created in 1949 and included 30 different countries that promised collective military defense. This organization was created at the beginning of the Cold War (1947-1991) and included most of the countries that belonged to the Western or Capitalist Bloc. Indeed countries of this bloc decided to create NATO to defend themselves from a possible attack by the countries of the Eastern or Communist Bloc such as the Soviet Union. On the other hand, the Eastern bloc created a similar organization known as the Warsaw Pact.