The correct answer is D) Water-antifreeze mixture. The liquid used in the liquid P/V (Pressure/Vacuum) breaker on a vessel is typically a water-antifreeze mixture. This mixture helps prevent the liquid from freezing in cold weather conditions, ensuring the proper operation of the P/V breaker. The P/V breaker is a safety device that allows air to flow into or out of a cargo tank to prevent the tank from becoming over-pressurized or under-pressurized. The other options are incorrect because: A) Hydraulic oil is used for different systems on the vessel and would not be suitable for the P/V breaker. B) Oil from the cargo would not be a suitable liquid for the P/V breaker. C) Distilled water alone would freeze in cold weather and would not be appropriate for the P/V breaker.