Insulated conductors used in wet locations shall ___.

Insulated conductors used in wet locations must be insulated and specifically rated for wet locations to ensure safety and reliability. This requirement is crucial because conductors in environments exposed to moisture can lead to electrical failures, short circuits, and serious safety hazards such as electric shock or fire. Conductors that are properly rated for wet conditions typically have coatings or materials that prevent moisture ingress and maintain integrity, thus ensuring they operate effectively under those conditions.

Options that suggest they must always be covered or be of a high voltage type do not address the essential need for the conductors themselves to be designed and tested for wet environments, which can lead to misuse or inappropriate applications if interpreted incorrectly. Therefore, the correct answer emphasizes the importance of using conductors that are both insulated and rated for the specific risks associated with wet locations.