Which of the listed sections of an emergency switchboard is used to supply power for alarm signals under emergency conditions?

Correct Answer: Option A — The 24 volt DC bus

46 CFR 112.15-1 requires emergency lighting and alarm systems to be powered by an independent source. The 24V DC bus is standard for these critical circuits, as it allows operation via battery banks if the main and emergency generators are unavailable, ensuring essential safety alarms remain functional.