Which of the following is NOT permitted to identify an insulated grounded conductor of 6AWG or smaller?

The correct response that identifies what is NOT permitted for an insulated grounded conductor of 6 AWG or smaller is based on the established conventions for color coding of grounding conductors in electrical systems.

For conductors that are intended to be grounded, the National Electrical Code (NEC) outlines specific requirements. According to these guidelines, an insulated grounded conductor can either have white or gray insulation, which identifies it as a neutral conductor. A solid green insulation indicates a grounding conductor. However, for smaller gauge wires, the use of three continuous white stripes on green insulation is not considered compliant since it does not align with the code's specifications for identifying grounded conductors clearly.

The use of three continuous stripes of white on green can create confusion about the conductor's purpose since green is strictly reserved for grounding and white or gray for neutral grounding. Thus, only solid green and strictly white or gray insulated conductors fulfill the requirements for 6 AWG or smaller insulated grounded conductors.

The other options, such as a white or gray conductor or solid green, are explicitly allowed under the code. Hence, the option of three continuous white stripes on green insulation is the only choice that does not meet the necessary criteria for identifying insulated grounded conductors in that specific size category