A towing winch, that handles a wire towline, must have all of the following EXCEPT a _________.

Correct Answer: Option B — source of emergency power to operate the winch

Towing winches require reliable braking and spooling mechanisms under 46 CFR standards, but an independent source of emergency power is not mandatory. Winches must feature a manual backup brake operable without power, but emergency power for the motor itself is not a strict regulatory requirement.