What action should you take if a shipmate chokes suddenly, cannot speak, and starts to turn blue?

Correct Answer: Option C — perform the Heimlich maneuver

A complete airway obstruction demands immediate abdominal thrusts, known as the Heimlich maneuver, to force residual air from the lungs and expel the foreign object. Universal signs of choking, including inability to speak and cyanosis, require swift intervention before unconsciousness occurs to prevent fatal asphyxiation.