Explanation:

- Option 1: WTO - The World Trade Organization (WTO) focuses on international trade regulations and does not release the Global Hunger Index.

- Option 2: WHO - The World Health Organization (WHO) focuses on global health issues but is not responsible for releasing the Global Hunger Index.

- Option 3: IFPRI - The Global Hunger Index is released by the International Food Policy Research Institute (IFPRI) along with Concern Worldwide and Welthungerhilfe.

- Option 4: FAO - The Food and Agriculture Organization (FAO) of the United Nations deals with global food security but does not release the Global Hunger Index.