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: Microbiology
[{'content': 'Most common post splenectomy infection is: \nSelect and explain. \nA. Pneumococcus, B. Meningococcus, C. Staphy lococcus, D. Corynebacterium', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Pneumococcus', 'role': 'assistant'}]