The technique that is used to remove water from the lungs of a drowning victim is the application of back blows and chest thrusts. This method is part of first aid protocols to clear an airway in cases where a person may be choking or in distress and has inhaled water.
When applied correctly, back blows can help dislodge fluid from the lungs, allowing for easier breathing and helping to restore air exchange. The protocol typically involves delivering firm blows between the shoulder blades while the victim is positioned in a way that allows gravity to assist in the expulsion of water. Chest thrusts are used in tandem with back blows to further help dislodge any obstruction or fluid hindering the person's ability to breathe.
The other options listed do not specifically address the removal of water from the lungs in a drowning situation. Cardiac compressions focus on maintaining blood circulation during cardiac arrest, abdominal thrusts are utilized primarily for choking when an object is lodged in the throat, and the head-tilt maneuver is used to open the airway, not to expel water. Thus, the choice of back blows and chest thrusts is most aligned with the goal of clearing fluid from the lungs of a drowning victim.