Final answer:
The master's responsibility to ensure a ship is seaworthy is outlined in the Hague-Visby Rules, which set the international standard for the carriage of cargo on merchant ships.
Step-by-step explanation:
The responsibility of the master to ensure that a ship is seaworthy and in a fit state to safely carry a shipper's cargo falls under b) the Hague-Visby Rules. These rules are a set of international conventions that establish minimum standards for the carriage of cargo under a bill of lading. These include the ship's condition, the packaging of cargo, and the preparation, loading, handling, stowage, carriage, custody, care, and discharge of the goods carried. It does not relate to the Sussex Pledge or announcing and inspecting vessels as with submarines; rather, it ensures the ship itself is capable of safely transporting its cargo.