A compartmentalized floor area of a building is subdivided with fire‑resistive:

• A. Partitions or walls
• B. Doors
• C. Windows
• D. Beams

Answer: (A)

The key idea is compartmentalization: fire-resistive barriers create separate areas within a floor to slow fire, heat, and smoke from spreading. The boundary that defines a compartment is formed by fire-resistive partitions or walls rated to withstand fire for a specified period. Doors within that boundary are important components and should be fire-rated and self-closing, but they are openings in the barrier rather than the boundary itself. Windows are openings that can compromise the barrier unless they are specifically rated and protected, so they’re not the primary means of dividing the space. Beams are structural elements and do not establish fire compartments.