Under the U.S. Aids to Navigation System on the Western Rivers, the buoys marking the starboard side of the channel when going upstream will be __________.

Correct Answer: Option A — red

Returning upstream (ascending) on Western Rivers follows the standard lateral system where the starboard side of the channel is marked by red aids, typically red nun buoys, in accordance with the "red right returning" rule of 33 CFR 62.25.