This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2019, Subject name: Social & Preventive Medicine
[{'content': 'Yellow fever vaccine is valid for; \nSelect and explain. \nA. Life long, B. 10 years, C. 5 years, D. 20 years', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The term of validity of the yellow fever vaccine ceificate has been changed from 10 years to life long YELLOW FEVER Vaccine- Route of YF vaccine -Subcutaneous Strain used -17 D Site of administration - at inseion of deltoid Dose: 0.5ml (irrespective of age)', 'role': 'assistant'}]