The lack of a certain feature on older heat detectors makes it difficult to track down the cause of an alarm. What is it they lack?

• A. Remote audible indicator
• B. Built-in camera
• C. Self-test routine
• D. Visual triggers that tell which device was activated

Answer: (D)

The key idea here is knowing exactly which detector tripped so responders can quickly locate the source. Visual indicators on each detector that show when and which unit activated give immediate, on-site feedback about the specific device involved. When older heat detectors lack these visual cues, you’re forced to search or rely on a centralized system signal that may not map directly to a single device, making it harder and slower to pinpoint the origin of the alarm.

Other features might help in general, but they don’t directly identify the activating unit as reliably. A remote audible indicator can signal that an alarm occurred, but it doesn’t always tell you which detector triggered. A built-in camera isn’t a standard feature on older heat detectors. A self-test routine confirms the device is functional but doesn’t reveal which device actually activated during an event.