Which lights is a vessel not under command making way at night is required to show?

Answer: A — Two all-round red lights in a vertical line, sidelights, and a stern light

A vessel not under command, when making way at night, is required to display specific visual signals to communicate its status to other vessels. The requirement for this type of vessel is to show two all-round red lights in a vertical line, sidelights, and a stern light. The two all-round red lights indicate that the vessel cannot maneuver as required by the navigation rules due to some exceptional circumstance. This warning is crucial for other vessels to recognize that the vessel not under command might not be able to take evasive actions, thus maintaining safe distances. The inclusion of sidelights (red and green) further defines the vessel's orientation—red on the port side and green on the starboard side—while the stern light provides visibility from the back of the vessel. Together, these lights create a clear and recognized signal that aligns with the International Regulations for Preventing Collisions at Sea (COLREGs), ensuring that other vessels can navigate safely in the vicinity of the vessel that is not under command. The other options do not match the required lighting configuration for a vessel under the described circumstances, as they suggest incorrect lights or arrangements that do not comply with the established navigation rules for vessels not under command.