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
What is the recommended duration of quarantine for yellow fever? 
Select and explain. 
A. 3 days, B. 6 days, C. 9 days, D. 12 days
B: 6 days
Answer: B: 6 days 
Explanation: A traveller should be placed in a mosquito proof ward for 6 days from the date of leaving an infected area. Ref: Park 21st edition, page 259.