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: Pediatrics
[{'content': 'Drug of choice for pertussis in children is \nSelect and explain. \nA. Penicillin, B. Erythromycin, C. Ampicillin, D. Azithromycin', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]