The correct answer is - C. North Atlantic Treaty Organization (NATO).
The United States are the alpha and omega in the NATO. They are like the mother country of all other country members and is always the country that leads the politics and actions performed from the organization, so most countries come as a satellite countries that in return for being protected by the United States are giving them support. Also, the United States are by far the strongest military force in the organization, on its own it has stronger military than all the other members combined.