Which of the following is BEST used for fire safety to prevent toxic fumes during a fire?

Multi-mode refers to the light propagation mode in fiber optic cables and has no bearing on the fire safety or smoke toxicity rating of a cable.

Single-mode is a fiber optic classification describing the core diameter and transmission method, not a fire-safety cable rating.

Standard PVC-jacketed cables emit toxic hydrogen chloride gas and dense black smoke when burned, making them the unsafe alternative that plenum cable is specifically designed to replace.

Plenum cables use jacket materials such as low-smoke PVC or FEP (fluorinated ethylene propylene) that meet NEC Article 800 fire and smoke standards. When exposed to fire, they resist flame spread and emit far fewer toxic gases compared to standard cables, which is critical in air ducts and ceiling spaces where toxic fumes can spread throughout a building via the HVAC system.