This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Medicine
[{'content': 'A 33-year-old man is complaining of feeling thirsty all the time and passing more urine than usual. His physical examination is normal, except for a JVP at the sternal angle. His serum sodium is 150 mEq/L, glucose 120 mg/dL, and osmolality 315 mOsm/kg. The urine sodium is 20 mE/L and osmolality 260 mOsm/kg. Which of the following drugs is most likely to cause this disorder? \nSelect and explain. \nA. lithium, B. cyclophosphamide, C. barbiturates, D. nicotine', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Nephrogenic diabetes insipidus can be caused by drugs such as lithium, metabolic factors, vascular disease, ureteral obstruction, and genetic factors.', 'role': 'assistant'}]