A fire alarm's secondary power can be derived from which of the following options?

The secondary power for a fire alarm system is crucial for ensuring reliable operation in case of a primary power failure. Battery or generator-based systems serve as excellent backup options, as they provide a consistent and ready source of energy to keep the fire alarm functioning during emergencies, such as power outages. Batteries can recharge when primary power is available, while generators can supply power for extended periods. This duality ensures that fire alarms remain operational regardless of external power conditions, enhancing the safety measures in place.

Solar power and wind energy, while renewable, may not provide the immediate reliability and consistent output required for critical fire alarm systems when needed most. Additionally, relying solely on AC power does not account for potential power outages, making it an insufficient choice for a secondary power source. Hence, the correct answer effectively highlights the most reliable and conventional methods for ensuring continuous operation of fire alarm systems during power failures.