Non-current carrying metal parts of cord and plug connected equipment may be grounded by what?

The correct answer is grounded by Equipment Grounding Conductors (EGC). This is crucial because EGCs are specifically designed to provide a safe path for ground faults, thereby preventing electric shock and protecting both equipment and individuals from electrical hazards.

In electrical systems, non-current carrying parts of devices—like the metal housing of an appliance—must be grounded to ensure safety. The EGC ensures that if any fault occurs and the current strays outside of its intended path, it is directed safely into the ground. This grounding helps to trip circuit breakers or blow fuses, cutting off the power to the equipment and reducing the risk of electric shock.

Other options, though related to electrical systems, do not serve the same grounding purpose adequately. Dedicated circuit conductors and separate grounding conductors might provide power and ground respectively, but they do not specifically refer to the equipment grounding function provided by EGCs. Current-carrying conductors are designed to carry electrical current and should not be relied upon for grounding purposes because doing so can create safety hazards.