Final answer:
The organization formed by Clara Barton in 1881 is the International Red Cross and Red Crescent Movement, known for its humanitarian efforts worldwide. The WHO, under the UN, focuses on health issues and is not the organization Barton founded. The UN itself, established after WWII, addresses international peace and security.
Step-by-step explanation:
The worldwide organization that was formed by Clara Barton in 1881 to promote neutral humanitarian care to victims of war is the International Red Cross and Red Crescent Movement. Clara Barton, known for her work in nursing and supporting soldiers during the American Civil War, founded the American branch of this international organization, which is dedicated to providing emergency assistance, disaster relief, and education in communities affected by conflicts or natural disasters. As one of the most recognized organizations in the world, the Red Cross is known for its significant humanitarian efforts, such as the assistance provided during the Berlin Airlift and aid to refugees during the crises in Bosnia and Kosovo. Another prominent organization founded under the umbrella of the United Nations is the World Health Organization (WHO), which focuses on global health issues. Although the WHO is committed to improving health standards worldwide, it was not the organization founded by Clara Barton. As for other bodies like the United Nations (UN), which was established after World War II to maintain international peace and security, they play different roles in the sphere of international relations and humanitarian aid.