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': 'Hyperbaric oxygen is dangerous because it: \nSelect and explain. \nA. Decreases displacement of 02 from kHb, B. Decreases respiratory drive, C. Enzyme damage, D. Is toxic to tissures', 'role': 'user'}, {'content': 'Answer: D \nExplanation: D i.e. Is toxic to tissuesDecreased cerebral blood flow due to cerebral vasoconstriction caused by high 02 tension is its protective effectQ (not toxic). Which protects brain from free radicle injury.', 'role': 'assistant'}]