Final answer:
The best next course of action when treating a patient with carbon monoxide poisoning is to administer high flow oxygen at 15 liters via a non-rebreather mask and ensure rapid transport to a medical facility.
Step-by-step explanation:
The best next course of action when treating a patient with carbon monoxide poisoning is to administer high flow oxygen at 15 liters via a non-rebreather mask and ensure rapid transport to a medical facility (Option A). This is because oxygen hastens the dissociation of carbon monoxide from carboxyhemoglobin, effectively turning it back into hemoglobin. Administering oxygen via non-rebreather mask significantly reduces the half-life of carbon monoxide in the bloodstream, thus preventing further poisoning.