Concept:Public corporations are government-owned bodies set up to provide services for public benefit, not private profit-making businesses.Explanation:The Joint Admissions and Matriculation Board is a government agency established by law.The Nigerian Steel Development Authority is also a government-owned public corporation.The Nigeria Railway Corporation is a state-owned public corporation providing railway services.However, Zenith Bank plc is a private commercial bank owned by shareholders and operated for profit.Therefore, Zenith Bank plc is not a public corporation.Answer:C. Zenith Bank plc