Which of the following is not part of the World Bank Group of Institutions?

The World Bank Group (WBG) is a family of five international organizations that make leveraged loans to developing countries. It is the largest and most famous development bank in the world and is an observer at the United Nations Development Group. Its five organizations are the International Bank for Reconstruction and Development (IBRD), the International Development Association (IDA), the International Finance Corporation (IFC), the Multilateral Investment Guarantee Agency (MIGA) and the International Centre for Settlement of Investment Disputes (ICSID). The Asian Infrastructure Investment Bank (AIIB) is a multilateral development bank that aims to support the building of infrastructure in the Asia-Pacific region.