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: Social & Preventive Medicine
[{'content': 'What is the duration of validity of yellow fever vaccination? \nSelect and explain. \nA. 2 years, B. 5 years, C. 10 years, D. 12 years', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The validity of ceificate of vaccination for yellow fever begins 10 days after vaccinatuion and is valid upto 10 years. Ref: Park 21st edition, page 259.', 'role': 'assistant'}]