Distress flares and smoke signals for small passenger vessels __________.

Correct Answer: Option D — All of the above

46 CFR 180.68 mandates that distress signals be USCG-approved, stored in watertight containers, and marked with expiration dates not exceeding 42 months from manufacture. These requirements ensure that pyrotechnics remain reliable and effective for signaling distress, regardless of the vessel's route or the duration of its voyage.