Under the IALA-B Buoyage System, when entering from seaward a lateral system buoy to be left to starboard may display which of the topmarks shown in illustration D046NG below?

Correct Answer: Option A — A

Under IALA-B, a starboard hand buoy (entering from seaward) is red and may carry a red conical topmark. Illustration D046NG depicts this standard shape. Per the USCG Aids to Navigation System, topmarks are used to provide positive identification of lateral marks, ensuring safe passage in complex channel configurations.