This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Poisoning, Subject name: Forensic Medicine
[{'content': '% of COHb than can cause death - \nSelect and explain. \nA. 70%, B. 82%, C. 75%, D. 80%', 'role': 'user'}, {'content': 'Answer: B \nExplanation: % of CoHb Clinical features 0 - 10 No symptoms 10 - 20 Tightness across forehead Slight headache Dilatation of cutaneous blood vessels 20 - 30 Headache Throbbing in temples 30 - 40 Severe headache Weakness Dizziness Dimness of vision Nausea and vomiting Collapse 40 - 50 Same as above plus greater possibility of collapse or syncope Increased respiration and pulse 50 - 60 Syncope Coma with intermittent convulsions Cheyne-strokes respiration 60 - 70 increasing coma 70 - 80 deep coma,absnet reflexes above 80% causes death from respiratory arrest REF;THE SYNOPSIS OF FORENSIC MEDICINE:KS NARAYANA REDDY;28th EDITION;PAGE NO 359', 'role': 'assistant'}]