Which type of conduit is required to be protected by a steel plate if located too close to wood members?

The correct choice indicating the type of conduit that requires protection by a steel plate when located close to wood members is based on the specific use and characteristics of the conduit types listed. In this case, Type LFNC (Liquidtight Flexible Nonmetallic Conduit) is designed for flexibility and is often used in locations where it may be exposed to physical damage.

LFNC is nonmetallic, which means it does not have the same protective qualities as metallic conduits. When installed near wood members, there is an increased risk of damage due to the potential for impact or other stresses, which necessitates additional protection measures, such as the installation of a steel plate. This requirement helps ensure that the conduit remains intact, minimizing the risk of electrical hazards.

In contrast, the other types of conduit like Rigid Metal Conduit (RMC), Intermediate Metal Conduit (IMC), and PVC Conduit have different physical properties that already provide a significant degree of protection or may not be subjected to the same hazards that necessitate extra protective measures when in proximity to wood. Their materials and construction either offer inherent strength or are suitable for environments where the added protection is deemed unnecessary.