This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Central Nervous system, Subject name: Pharmacology
[{'content': 'The following symptoms may be seen in opium withdrawal: \nSelect and explain. \nA. Constipation, B. Lacrimation, C. Dry nose and mouth, D. Constipation', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Withdrawal symptoms of opium are lacrimation, sweating, yawning, anxiety, apprehension, restlessness, rhinorrhoea, and tremors seen 8-12 hours after the last Dose. Ref: KD Tripathi 8th ed.', 'role': 'assistant'}]