The correct answer is D. 193.
The United Nations (UN) is an international organization founded in 1945 after the Second World War by 51 countries committed to maintaining international peace and security, developing friendly relations among nations and promoting social progress, better living standards and human rights. Due to its unique international character, and the powers vested in its founding Charter, the Organization can take action on the issues confronting humanity in the 21st century, such as peace and security, climate change, sustainable development, human rights, disarmament, terrorism, humanitarian and health emergencies, gender equality, governance, food production, and more.
The UN System is made up of the UN itself and a family of specialized agencies, funds and programmes that are governed by the UN General Assembly. The UN System works on a wide range of fundamental issues, from sustainable development, environment and refugees protection, disaster relief, counter terrorism, disarmament and non-proliferation, to promoting democracy, human rights, gender equality and the advancement of women, governance, economic and social development and international health, clearing landmines, expanding food production, and more, in order to achieve its goals and coordinate efforts for a safer world for this and future generations.
As of 2023, there are 193 Member States of the United Nations. The newest Member State is South Sudan, which joined the Organization on 14 July 2011.