Question 477 Rules of the Road

The correct answer is D) It is a white light. According to international regulations, the light used with a vessel's whistle must be a white light. This white light is used to attract attention and indicate that the whistle is about to be sounded, regardless of the time of day. It is not limited to use only at night, nor is it specific to situations where the whistle is broken. The other answer choices are incorrect as they do not accurately reflect the international requirements for the type of light to be used with a vessel's whistle.