You have berthed in a port area with other tank vessels. What signal is displayed by a vessel to indicate it is transferring flammable or combustible liquid cargo?

Correct Answer: Option C — A red light visible all around the horizon

USCG regulations mandate that transferring flammable or combustible liquids requires displaying a prominent red light visible all around the horizon during hours of darkness, supplemented by a red flag (Baker flag) during daylight operations.