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: Forensic Medicine
[{'content': 'Poisoning with all the following causes constriction of the pupils except - \nSelect and explain. \nA. Dhatura, B. Morphine, C. Organophosphorus compounds, D. Pontine hemorrhage', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Morphine, organophosphates and pontine hemorrhage cause miosis (constriction of pupil).\nDhatura causes mydriasis (dilatation of pupil).', 'role': 'assistant'}]