Final answer:
An unattended coffee machine left on with no coffee in it is a fire hazard because it can overheat or short circuit, posing a risk of fire and potential for extreme physical danger.
Step-by-step explanation:
The question addresses the identification of potential fire hazards while on patrol. Among the listed options, c) Coffee machine left on with no coffee in it may be considered a fire hazard. This is because an unattended appliance that generates heat, like a coffee machine, can overheat or short circuit, especially if something is wrong with the electrical outlet, potentially causing a fire. A slippery floor or a damaged handrail, while they are safety hazards, they do not specifically pose a fire risk.
The scenario of a coffee machine left on illustrates the uncertainty over whether a serious fire hazard awaits. There is the potential for extreme physical danger due to the possible ignition of materials nearby or damage to the machine itself if it overheats.