This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
[{'content': 'Regarding carbon monoxide poisoning, the wrong statement \nSelect and explain. \nA. Oxygen dissociation curve shifted to right, B. Oxygen dissociation curve shifted to left, C. COHb is formed, D. Hyperbaric oxygen can be used', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Since Hb has more affinity to CO than oxygen, it results in anaemic hypoxia. PO2 remain normal as it is the dissolved form. Hb-O2 dissociation curve shifts to left. Treatment for CO poisoning is by hyperbaric oxygen. But 95% O2 + 5% CO2 can also be used. CO is a gaseous vasodilator.', 'role': 'assistant'}]