Which of the following defines the main purpose of the United Nations?

The main purpose of the United Nations is to facilitate cooperation in international law and security. This organization was established after World War II with the primary aim of fostering international cooperation and preventing conflicts by providing a platform for dialogue among countries. The UN works to maintain peace and security through various means, such as conflict resolution, peacekeeping missions, and promoting human rights.

While promoting economic development is an important aspect of some UN initiatives, it is not the overarching purpose of the organization. Similarly, overseeing international trade and establishing a global currency are specific functions that do not encompass the full scope of the UN’s mission. The focus on law and security allows the UN to address a wide range of global issues, including humanitarian crises, international relations, and the ongoing need for diplomacy between nations. Thus, option B accurately captures the essence of the UN's foundational goals.