Final answer:
GFCI protection is required for all kitchen receptacles serving countertop surfaces, regardless of their distance from the sink, according to the NEC.
Step-by-step explanation:
According to the National Electrical Code (NEC), which sets the standards for electrical safety in the United States, GFCI protection is generally required for all kitchen receptacles that serve countertop surfaces. This is due to the potential hazard that a leakage current presents, especially in areas where water is present and can provide a good path for electricity to ground, such as kitchens and bathrooms. GFCI protection detects differences in current between the hot and neutral wires which may occur if the electrical current finds an alternative path, potentially through a person, which could be hazardous.
So when changing a 3-wire grounded receptacle in a dwelling unit kitchen, even if the receptacle is more than 6 feet from the sink, it must still be protected by a GFCI.
Hence, the correct answer is A) GFCI protection is required for all countertop receptacles.