The owner, agent, Master or person-in-charge of a "T-Boat" involved in a marine casualty causing injury that requires professional medical treatment must __________.

Correct Answer: Option D — All of the above

46 CFR Part 4 mandates that the owner or Master must report marine casualties involving professional medical treatment. This includes immediate notification to the nearest Coast Guard Sector, filing Form CG-2692 within five days, and preserving all relevant voyage records, logs, and evidence for subsequent Coast Guard marine casualty investigations.