A signal indicating an emergency requiring immediate action in a fire alarm system is a(n) ___.

• A. trouble
• B. alarm
• C. supervisory
• D. code red

Answer: (B)

In fire alarm systems, signals are categorized to show different kinds of conditions. The one that means there’s an emergency and people must act immediately is the alarm signal. It’s produced by detectors or manual pull stations and triggers audible and visual alerts so occupants evacuate and responders are notified. This is different from trouble signals, which point to faults in the system that need service but don’t require immediate evacuation, and supervisory signals, which indicate monitored conditions affecting safety (like a valve or device status) but aren’t an immediate life-safety evacuation cue. The term code red isn’t a standard technical category for fire alarm signaling, so it isn’t the appropriate choice in this context.