This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epidemiology, Subject name: Social & Preventive Medicine
[{'content': 'All of the following vaccine are recommended for elderly travelers, except- \nSelect and explain. \nA. Influenza, B. Pneumococcal, C. Tetanus, D. Measles', 'role': 'user'}, {'content': 'Answer: D \nExplanation: .', 'role': 'assistant'}]