Which of the following describes the best way to open airways to an unresponsive victim who has no sign of neck or head injury?

Tilting the head back and lifting the chin is the best way to open the airways of an unresponsive victim who shows no signs of neck or head injury. This maneuver, known as the head-tilt, chin-lift technique, helps to reposition the airway so that it is not obstructed by the tongue or other tissues. In an unresponsive individual, the muscles that control the airway can relax, allowing the tongue to fall back and block the airway. By tilting the head back and lifting the chin, you can create a clearer path for airflow, facilitating effective rescue breathing if needed.

Other options, such as pulling the tongue forward, are not a standard method for opening the airway and can be less effective or even harmful. Performing the Heimlich maneuver is not applicable in this scenario, as it is used to relieve choking in conscious individuals, not to open airways in unresponsive victims. Placing the victim in a prone position (face down) would actually obstruct the airway rather than open it, which could lead to suffocation.

In emergency situations, it is crucial to use the most effective and recognized techniques, and the head-tilt, chin-lift method is a primary component of basic airway management.