Which of the following does not require cargo transfer operations on a tank vessel to be stopped?

Correct Answer: Option C — a tug comes alongside while the tanker is loading grade D and E cargoes

33 CFR 156.120 mandates stopping transfer operations for emergencies like fires or spills. However, a tug coming alongside is a routine operational event. While caution is required, it does not necessitate an immediate emergency shutdown of cargo transfer, provided standard mooring and safety protocols are maintained during the operation.