What is a significant danger for occupants remaining in a room when a carbon dioxide extinguishing system is discharged?

The danger posed to occupants remaining in a room when a carbon dioxide extinguishing system is discharged primarily revolves around the potential for asphyxiation due to the displacement of oxygen in the environment. Carbon dioxide systems work by displacing oxygen to smother a fire, which can inadvertently create a life-threatening situation for anyone still inside the enclosure.

Specifically, when carbon dioxide is released, it can rapidly decrease the amount of breathable air within the space. This lack of oxygen can lead to unconsciousness or even death if individuals do not evacuate promptly. The body requires a certain level of oxygen to function properly, and when that level falls, the result can be severe, including loss of consciousness and asphyxiation. Thus, the correct answer highlights a critical safety hazard that must be addressed in scenarios involving the use of carbon dioxide extinguishing systems.

Other options present dangers that do not directly relate to the primary risk posed by carbon dioxide systems in this context. For instance, excessive heat, burns, or pressure-associated risks are less likely outcomes associated with the action of discharging carbon dioxide in a fire suppression situation when the primary concern is the effect of oxygen displacement on human occupants.