For a high-rise operation, if using an elevator, the floor operator must stop _____ floors below the fire floor.

In high-rise operations, safety protocols dictate that if firefighters are using an elevator to access the fire floor, the elevator should stop a specified number of floors below the fire floor. Stopping two floors below the fire floor is the correct procedure because it allows firefighters to exit the elevator while avoiding potential hazards, such as smoke or fire that could compromise their safety. It also provides a buffer zone to ensure that they are not directly exposed to the dangerous conditions typically found on or immediately above the fire floor. This minimal distance helps maintain the safety of the operation while still allowing for a timely response.

Other options indicate stopping either one, three, or four floors below, which may not provide the necessary precautions against smoke, heat, and fire conditions as effectively as stopping two floors below. Such considerations are critical in emergency response scenarios to ensure the safety and efficacy of operations carried out by firefighters.