A U.S. Coast Guard icebreaker may use all of the following distinctive lights when escorting ships in ice EXCEPT __________.

Correct Answer: Option A — a single blue rotating light

USCG icebreakers do not display a single blue rotating light when escorting ships; blue lights are reserved strictly for law enforcement vessels. Authorized icebreaking escort lights include amber rotating lights and red aircraft warning lights per maritime navigation rules.