What type of light pattern may a special mark buoy display?

A special mark buoy is designated to indicate a specific area or feature, such as a cautionary zone or a part of the waterway that requires special attention, which could include spoil ground, submerged pipelines, or other underwater hazards. The light pattern used for special marks is typically a quick flashing yellow light. This distinctive pattern helps mariners easily identify the buoy's specific function and purpose amidst other navigational aids. By using a quick flashing yellow light, the special mark buoy effectively communicates its message of caution to vessels approaching the area, ensuring that operators remain alert and aware of any potential hazards or areas requiring special attention.

The other options do not accurately reflect the designated light pattern for special mark buoys; therefore, they are not suitable for this particular application.