Which of the following best describes automatic detection in a fire alarm system?

• A. Manual activation by a person
• B. Detector-based triggering of alarms
• C. Visual-only indicators
• D. No sensors involved

Answer: (B)

Automatic detection means the fire alarm is triggered by sensors without human action. Detectors such as smoke, heat, or flame sensors monitor for signs of fire and, when they detect them, send a signal to the fire alarm control panel to start all alarms. This is different from manual activation, where a person must pull a switch; visual-only indicators are passive and do not start the alarm; and a system with no sensors cannot provide automatic detection.