Which type of material is both ultraviolet and flame resistant?

The correct choice identifies a type of material designed specifically to withstand various environmental stressors, including ultraviolet (UV) light and flame. Type D materials are engineered for increased durability under outdoor conditions, making them suitable for use in applications exposed to sunlight, which can degrade lesser materials over time due to UV radiation.

Moreover, these materials adhere to safety standards regarding flame resistance, meaning they are treated or constructed to resist ignition and limit flame spread, thus enhancing safety in scenarios where fire is a risk. Such properties are vital for outside plant installations, which may be located in environments where both UV exposure and fire hazards are significant considerations.

While other material types may possess certain beneficial qualities, they do not uniformly offer the same level of UV and flame resistance, which is crucial for ensuring long-term performance and compliance with safety regulations in outdoor applications. The combination of these attributes in Type D materials makes them particularly suitable for the needs of outside plant design.