Conduit type D is described as which?

• A. Ultraviolet and flame resistant
• B. Thin wall, requires concrete encasement
• C. Thick wall, direct buried
• D. Not used for straight line conduit

Answer: (A)

Conduit type D is defined by its ability to withstand sunlight and meet flame-retardant requirements. In outside plant installations, you choose this type where the conduit will be exposed to ultraviolet radiation and needs to be flame resistant, so ultraviolet and flame resistance is the best description. The other options describe features that align with different conduit classifications or installation conditions (such as wall thickness or burial method), which aren’t the defining traits of Type D.