The correct answer is C. 1949.
The North Atlantic Treaty Organization (NATO) is an intergovernmental military alliance between 30 member states – 28 European countries, the United States, and Canada. The organization implements the North Atlantic Treaty that was signed on 4 April 1949.
NATO constitutes a system of collective security, whereby its independent member states agree to mutual defense in response to an attack by any external party. NATO’s headquarters are located in Haren, Brussels, Belgium, while the headquarters of Allied Command Operations is near Mons, Belgium.
The Treaty of Brussels was signed on 17 March 1948 by Belgium, the Netherlands, Luxembourg, France, and the United Kingdom. The treaty was a mutual defense pact in response to the perceived threat of the Soviet Union. The treaty was later expanded to include the United States, Canada, Portugal, Italy, Norway, Denmark, Iceland, and Greece.
The North Atlantic Treaty was signed on 4 April 1949 by the 12 original members of NATO. The treaty states that an attack on one member state is considered an attack on all member states. The treaty also establishes a council of representatives from each member state to coordinate the alliance’s activities.
NATO has played a major role in the Cold War, the War in Afghanistan, and the Libyan Civil War. NATO is currently involved in a number of peacekeeping and training missions around the world.