Answer:
B. The room temperature is only slightly increased.
Explanation:
In case of a small fire, there are always alternative options to put out the fire. So, the portable fire fire extinguishers should only be used in small fires as they are only capable of putting out these fires. Thus, they could be used only if the temperature of the room is slightly increased as there has to be an evacuation path and that has not to be obstructed in any case but if the smoke has filled the room, then the use of fire extinguisher may add to the sobriety of the fire. As we all know fire extinguishers release CO2 which prohibits the flow of oxygen to the fire but if the room is already smoky, the use of extinguisher may lead to the dual-source of releasing carbon dioxide which may faint the person and hence, worsening the situation.