On navigational aids, what does the light characteristic "Fl(2+1)" mean?

Correct Answer: Option B — Light flashes combined in groups, with a different number of flashes in each group

The characteristic Fl(2+1) denotes a composite group flashing light. This indicates that the light flashes in groups, with a different number of flashes in each group (two flashes followed by one). This specific pattern is used primarily on preferred-channel buoys to aid in positive identification.