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
For the yellow fever control, distance around airport to be kept free of Aedes breeding is 
Select and explain. 
A. 200m, B. 250m, C. 400m, D. 450m
C: 400m
Answer: C: 400m 
Explanation: None