The correct answer is: "They created the United Nations"
The United Nations is an intergovernmental organization that was founded in 1945, as a joint response of the international community to the atrocities and the losses suffered during WWII. It started with 51 member states and nowadays it has 193.
Its main aims are the following: keeping international peace and security, human rights protection, providing humanitarian aid, supporting sustainable development efforts and upholding international law.