The correct option is C UNICEF
The United Nations has 6 main organs like the General Assembly for all the members. The Security Council aims to maintain peace and security while the International Court of Justice (ICJ) acts as the judicial organ. Apart from this, other organs are the Economic and Social Council (ECOSOC), the Trusteeship Council and the Secretariat. WHO, UNESCO, and UNICEF are different agencies working in tandem with these organs and are not the main organs themselves.