The correct answer is option 2: In 1920. The League of Nations was established after the end of World War I in order to maintain peace and prevent future conflicts. It was established as part of the Treaty of Versailles, which was signed in 1919. The League of Nations aimed to provide a platform for international cooperation and to resolve disputes between nations peacefully. It was the first international organization of its kind and had 42 founding member states. The League of Nations carried out various initiatives such as overseeing mandate territories, addressing global health issues, and working towards disarmament. However, it ultimately failed to prevent World War II and was replaced by the United Nations in 1945.