Final answer:
c. Head tilt-chin lift for both 1 and 2 rescuers
The correct answer is option 'c', Head tilt-chin lift for both 1 and 2 rescuers, with the exception of a suspected spinal injury where a jaw thrust would be used.
Step-by-step explanation:
The proper technique for bag-mask ventilation varies depending on whether there is one rescuer or two. For a single rescuer, the preferred method is to perform the head tilt-chin lift maneuver while providing ventilations. This technique ensures that the airway is open for the artificial breaths to enter the lungs. Meanwhile, in situations where two rescuers are present, one rescuer can maintain the head tilt-chin lift while the other operates the bag-mask device, or if there is suspicion of a spinal injury, one rescuer can perform jaw thrust without head extension while the other provides ventilation. Therefore, the correct answer is option 'c', Head tilt-chin lift for both 1 and 2 rescuers, unless there is a risk of cervical spine injury, in which case a jaw thrust would be used while avoiding head extension.