According to Intemational Health Regulations, there is no risk of spread of yellow Fever if the Aedes aegypti index remains below :
Correct answer : A. 1%
Aedes aegypti index is the percentage of houses and their premises in a limited well defined area that show actual breeding of aedes aegypti larvae. It should be kept below 1%. In addition to this, airports and seaports should be free of aedes aegypti breeding up to 400m from their perimeters.