In port, where are the national ensign and union jack displayed on a commissioned ship?

The correct choice states that the national ensign is displayed on the flagstaff at the stern and the union jack is positioned on the jackstaff at the bow. This arrangement follows the established protocols for displaying flags on a commissioned ship while in port.

When a ship is in port, it is traditional to fly the national ensign to signify the ship's nation and its presence in the port area. The flagstaff at the stern serves as the primary location for the national ensign. Meanwhile, the union jack, which represents the flag of the Navy and is a symbol of maritime identity, is displayed on the jackstaff at the bow. This positioning not only adheres to naval customs but also ensures clear visibility and respect for the flags being flown.

The other options do not accurately reflect naval protocol. For example, placing the national ensign at the bow or the union jack at the stern does not conform to the rights and roles designated for each flag in maritime tradition.