When fighting a fire on a bulkhead using a portable carbon dioxide extinguisher, the stream should be directed at the __________.

Correct Answer: Option B — base of the flames, moving the horn from side to side, following the flames upward as they diminish

Under USCG National Maritime Center examination standards, the accepted correct answer is: base of the flames, moving the horn from side to side, following the flames upward as they diminish.