This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Communicable diseases, Subject name: Social & Preventive Medicine
To prevent Yellow Fever Aedes aegypti index should be less than? 
Select and explain. 
A. 0.50%, B. 1%, C. 2%, D. 5%
B: 1%
Answer: B: 1% 
Explanation: Aedes aegypti index is a house index and defined as the percentage of houses and their premises,in a limited well defined area, showing actual breeding of Aedes aegylti larvae. This index should not be more than 1% in towns and seapos in endemic areas to ensure freedom from yellow fever. Reference; Park&;s Textbook of preventive and social medicine, 24th edition.Pg no. 301