In which section is it stated when a conductor with white insulation may be used as an ungrounded circuit conductor?

The correct choice pertains to the specific regulations regarding the usage of conductors with white insulation. In section 200.7(C), the National Electrical Code (NEC) specifies the conditions under which a white or gray conductor, which is typically reserved for grounded conductors, may be utilized as an ungrounded (hot) circuit conductor.

This provision allows for exceptions in certain situations, such as in multi-wire branch circuits where a white conductor may be re-designated for use as an ungrounded conductor, provided that it is appropriately marked to avoid confusion with the grounded conductors. This regulation emphasizes the importance of clear identification, ensuring safety and compliance with electrical standards.

Sections 200.7(A), (B), and (D) deal with different aspects of conductor designation and color requirements but do not address the specific criteria for the use of white insulation as an ungrounded conductor. This distinction is crucial for electricians to understand how to handle conductors safely and in accordance with the code.