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': 'The 23 valent pneumococcal vaccine is recommended in all except - \nSelect and explain. \nA. CSF leak, B. Chronic cardiac disease, C. Children less than 2 years, D. Nephrotic syndrome', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]