Final answer:
When an existing two-wire, nongrounding-type receptacle is replaced with a GFCI receptacle, it should be replaced with a three-wire, grounding-type receptacle.
Step-by-step explanation:
When an existing two-wire, nongrounding-type receptacle is replaced in a location where the Code requires a GFCI (Ground Fault Circuit Interrupter) receptacle, it is permitted to be replaced by a three-wire, grounding-type receptacle.
The purpose of the GFCI receptacle is to protect against electrical shocks by quickly interrupting the circuit when it detects a difference in the current between the hot and neutral wires.
The grounding-type receptacle provides an extra safety measure by connecting the case of the appliance to the ground, preventing shocks in case of a fault.