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

Correct Answer: Option C — C

Under IALA Region A, the starboard side of a channel when entering from seaward is marked by green conical buoys. The corresponding topmark for a starboard hand buoy is a single green cone, which matches illustration C in the standard IALA buoyage reference diagrams.