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': 'Animal reservoir is seen in all except- \nSelect and explain. \nA. Rabies, B. Yellow fever, C. Influenza, D. Measles', 'role': 'user'}, {'content': "Answer: D \nExplanation: The only source of measles infection is a case of measles. Carriers are known to occur. Ref: 25th edition, Park's Textbook of Preventive and Social Medicine, Page no. 160", 'role': 'assistant'}]