Under the U.S. Aids to Navigation System on the Western Rivers, a preferred- channel buoy is __________.

Correct Answer: Option C — horizontally-banded red and green

On the Western Rivers, the U.S. Aids to Navigation System uses horizontally-banded red and green buoys to mark junctions or preferred channels. The color of the top band indicates the preferred channel side: red top for preferred channel to port, green top for preferred channel to starboard, when proceeding upstream.