সঠিক উত্তর হচ্ছে: the secretariat
ব্যাখ্যা: The chief administrative office of the UNO, which co-ordinates and supervises the activities of the UNO, is the secretariat. The secretary-general, the principal administrative officer of the United Nations, is elected for a five-year renewable term by a two-thirds vote of the General Assembly and by the recommendation of the Security Council and the approval of its permanent members.