What technique is required to open and assess an unresponsive patient's airway?

The correct technique for opening and assessing the airway of an unresponsive patient is the head-tilt/chin-lift maneuver. This method is the most commonly used for restoring airflow in situations where there are no signs of a cervical spine injury. When performed, it helps to lift the tongue away from the back of the throat and expand the airway, allowing for effective ventilation.

This technique involves tilting the patient's head back slightly and lifting the chin upwards. It's crucial for emergency responders and bystanders to use this method, especially when they need to perform rescue breaths or assess if the patient is breathing normally.

While there are other techniques like the jaw thrust and modified jaw thrust that are more appropriate in cases where a spinal injury may be suspected, the head-tilt/chin-lift is the standard approach for unresponsive patients without such concerns. Other options listed are either used in specific circumstances or do not effectively open the airway as required in this scenario.