Machines requiring single-phase power will have a qquad -prong plug. a. two b. five c. three d. four

c. three

Single-phase power systems use a plug with three prongs: a live (hot) wire, a neutral wire, and a ground wire. The live wire carries the current to the appliance, the neutral wire returns the current, and the ground wire is a safety feature to prevent electrical shocks. Therefore, option c is correct.