Which of the following is not a specialized agency of the United Nations ?

The World Health Organization (WHO), the International Monetary Fund (IMF), and the Food and Agriculture Organization (FAO) are autonomous Specialized Agencies brought into formal relationship with the United Nations under Articles 57 and 63 of the UN Charter. By contrast, the Organization of the Petroleum Exporting Countries (OPEC), founded in Baghdad in 1960, is an independent intergovernmental cartel of oil-producing states outside the UN system.