Under the IALA-A Buoyage System, a buoy indicating that the preferred channel is to port when entering from seaward, can have a __________.

Correct Answer: Option B — green light

When the preferred channel is to port, the buoy is red with a green horizontal band and displays a green light. This follows the IALA-A convention where the light color matches the color of the preferred channel side, ensuring clear identification for vessels approaching from the seaward direction.