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: Social & Preventive Medicine
[{'content': 'Treatment of choice for diphtheria carriers is: \nSelect and explain. \nA. Erythromycin, B. Tetracycline, C. Penicillin, D. DPT', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Erythromycin', 'role': 'assistant'}]