Final answer:
The Economic and Social Council (ECOSOC) is not a member of the World Bank Group; it is a principal organ of the United Nations.
Step-by-step explanation:
The member that is not part of the World Bank Group is b) The Economic and Social Council (ECOSOC). The World Bank Group is a family of five international organizations that make leveraged loans to developing countries. It is one of the world’s largest sources of funding and knowledge for developing countries. The five agencies that comprise the World Bank Group 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 Economic and Social Council (ECOSOC) is not part of the World Bank Group but rather one of the six principal organs of the United Nations responsible for coordinating the economic and social fields of the organization, specifically in regards to the 15 specialized agencies, the eight functional commissions and the five regional commissions under its jurisdiction.