Final answer:
In the case of a non-breathing and pulseless victim with a suspected spinal injury, the EMS provider should open the airway and check for breathing.
Step-by-step explanation:
When a single EMS provider finds a non breathing and pulseless victim of a motor vehicle accident (MVA) lying face down in the road and suspects a spinal injury, the appropriate action is to open the airway and check for breathing. This should be done before performing chest compressions, moving the victim, or administering oxygen.