Which situation is likely to trigger a panic alarm?

A panic alarm is specifically designed to be activated in emergencies where an individual's personal safety is at risk. In scenarios where there is an immediate threat to personal safety, such as an intruder entering a home or an assault in progress, a panic button provides a way for individuals to alert authorities quickly. This feature is intended to summon help as rapidly as possible in situations where time and safety are critical.

The other scenarios presented would not typically lead to a panic alarm being triggered. A false alarm due to a malfunction may create confusion but does not represent an actual threat, and routine testing does not involve any real danger, so there's no reason for a panic alarm to be activated. Similarly, a failure of the monitoring service might disrupt the communication of an alarm, but it does not pose an immediate personal risk that necessitates the urgent call for help that a panic alarm signifies.