What qualifies as an unnecessary alarm?

An unnecessary alarm is defined as one that does not reflect a legitimate fire emergency and does not warrant a response from emergency services. The situation described in the third choice, where an alarm is triggered by smoke from a lit cigarette in a non-smoking area, exemplifies this. In this case, the smoke does not indicate a fire or an imminent threat to safety, making the alarm unjustified. Such alarms can lead to panic, divert resources away from actual emergencies, and pose safety hazards due to unnecessary responses.

In contrast, the first option describes a malfunctioning detector, which is typically regarded as a technical issue rather than an unnecessary alarm since it can generate genuine concerns about safety and requires investigation. The second option, stating an alarm triggered by valid fire conditions, clearly represents a legitimate threat, so it cannot be categorized as unnecessary. The final option, regarding a delay in response from the fire department, speaks to issues of response times rather than the nature of the alarm itself. Thus, the correct identification of unnecessary alarms hinges on understanding the context and validity of the circumstances that trigger them.