Upon failure of the normal power supply, how is the emergency generator placed on the line to feed power to the emergency bus?

Correct Answer: Option D — automatic bus transfer device

An automatic bus transfer (ABT) device continuously monitors normal power supplies and automatically switches vital emergency loads to the emergency generator upon normal power failure. Per 46 CFR Subchapter J, this ensures uninterrupted power to essential safety services without requiring manual intervention during a casualty.