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: Pharmacology
[{'content': 'A 17 year old girl had been taking a drug for the treatment of acne for the last 2 years, which has lead to pigmentation. Which drug could it be? \nSelect and explain. \nA. Doxycycline, B. Minocycline, C. Azithromycin, D. Chlorpromazine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Both minocycline as well as chlorpromazine can cause pigmentation on long-term use.\nHowever, as the patient in question is being treated for acne, the answer should be minocycline. Antibiotics used in acne are erythromycin, clindamycin, tetracycline, doxycycline and minocycline.', 'role': 'assistant'}]