At the scene of a traffic collision, how should you open the airway of an unconscious victim with a suspected neck injury?

In the scenario of an unconscious victim with a suspected neck injury, the safest and most appropriate method for opening the airway is through the jaw-thrust maneuver. This technique minimizes any potential movement of the cervical spine, which is crucial when a neck injury is suspected.

By using the jaw-thrust maneuver, the responder places their fingers behind the angle of the victim's jaw and pushes the jaw forward, allowing the airway to open without tilting the head or neck. This is especially important because any movement of the neck could exacerbate an existing injury or lead to further complications, including increased risk of spinal cord damage.

The other methods mentioned are not appropriate in this context. Tilting the head back, for instance, could result in additional injury to the neck. Similarly, the chin lift maneuver typically involves manipulating the head and neck in a way that can compromise the cervical spine in an injured patient. Abdominal thrusts are used to relieve choking and are not related to airway management in an unconscious victim. Thus, the jaw-thrust maneuver is the correct choice given the circumstances.