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
Pneumonia is a complication of: 
Select and explain. 
A. Measles, B. Chickenpox, C. Infectious mononucleosis, D. Mastoiditis
A: Measles
Answer: A: Measles 
Explanation: 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.