Who must supervise functions aboard a tanker or tank barge such as connecting, disconnecting, and topping off?

Correct Answer: Option A — the person designated as "person in charge"

33 CFR 155.700 mandates that a designated Person-in-Charge (PIC) must supervise all critical oil transfer operations, including connecting, disconnecting, and topping off. The PIC is responsible for ensuring that all safety procedures are followed and that the transfer is conducted in accordance with the vessel's Operations Manual.