This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Infection, Subject name: Pediatrics
[{'content': 'Pneumonia is a complication of: \nSelect and explain. \nA. Measles, B. Chickenpox, C. Infectious mononucleosis, D. Mastoiditis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A. MeaslesImportant complications of measles include immunosuppression, Pneumonia, laryngitis, tracheitis, bronchitis, and flaring of mycobacterium tuberculosis infection. Gastrointestinal complications include diarrhea, appendicitis, hepatitis, and ileocolitis.', 'role': 'assistant'}]