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: Unknown
[{'content': 'Ramesh , 30 yrs old male,diagnosed case of CO poisoning presented with syncope or coma with intermittent convulsions, rapid respirations, tachycardia with a weak pulse and pink or red discolouration of the skin; estimated percentage of COHb : - \nSelect and explain. \nA. 30 to 40 %, B. 40 to 50 %, C. 50 to 60 %, D. 60 to 70 %', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]