INTERNATIONAL ONLY In a narrow channel, an overtaking vessel which intends to pass on the other vessel's port side would sound __________.

Correct Answer: Option C — two prolonged followed by two short blasts

COLREG Rule 9(e)(i) specifies that an overtaking vessel in a narrow channel intending to pass on the other vessel's port side must sound two prolonged blasts followed by two short blasts, signaling the specific maneuver requested in narrow waters.