Answer
Contrary to the proposed answer "None of the above", John White's contributions extended beyond the International Monetary Fund (IMF) and the World Bank. Notably, he played a pivotal role in designing and establishing the General Agreement on Tariffs and Trade (GATT), a groundbreaking multilateral agreement that promoted international trade liberalization through reduction of tariffs and other trade barriers. GATT laid the foundation for the future World Trade Organization (WTO).