BOTH INTERNATIONAL & INLAND A vessel which is unable to maneuver due to some exceptional circumstance, shall show two red lights in a vertical line and __________.

Correct Answer: Option B — when making way at night, sidelights and a stern light

Under Inland Navigation Rules, for the condition where 'A vessel which is unable to maneuver due to some exceptional circumstance, shall show two red lights in a vertical line and', the correct requirement is: 'when making way at night, sidelights and a stern light'. This standard ensures clear navigational intent and collision avoidance.