Fire barriers are used for area separations, hazard protection,

• A. FDC Manifolds, and OS&Y Valves
• B. Attic Access, and Utility Services
• C. Stairwells, and Shafts
• D. Fire Depository Boxes

Answer: (C)

Fire barriers are walls designed to resist fire and limit its spread between different parts of a building, helping to contain the incident and protect occupants. They are particularly important around vertical egress paths, so people can escape and smoke and heat don’t quickly travel between floors. That’s why protecting stairwells and shafts with fire barriers is the best fit—they keep the critical exit routes intact and reduce vertical fire spread.

Parts like FDC manifolds and OS&Y valves belong to the fire protection system itself, not to area-separating barriers. Attic access and utility services are not about creating fire-separated areas, and fire depository boxes are storage-related components, not barrier assemblies.