Which statement describes the typical use difference between bells and sirens in alarm systems?

• A. Bells are typically reserved for fire alarms; sirens for burglar alarms
• B. Bells and sirens serve the same purpose with different volumes
• C. Sirens are used only outdoors; bells only indoors
• D. Bells are used for gas detectors; sirens for heat detectors

Answer: (A)

The key idea is that signaling devices are tied to their typical purpose. Bells are traditionally used with fire alarms because their sound inside a building clearly announces an evacuation situation and supports life-safety procedures. Sirens are associated with burglar or security alarms and are designed to be loud and attention-grabbing to the outside world, deterring intruders and alerting neighbors or authorities. So, the usual distinction is that bells are for fire alarms inside the premises, while sirens are for burglar or security alarms outside the premises. This helps explain why the other options don’t fit: the difference isn’t just about volume or indoor versus outdoor in every case, nor does it align with detector types like gas or heat.