Polio is said to be eradicated if no case of polio by wild poliovirus occurs in an area for ?
Ans. is 'c' i.e., 3 years Ceification of polio eradication is conducted an regional bases. Each region can consider ceification only when all countries in the area demonstrate the absence of wild poliovirus transmission for at least three consecutive years.
1 year
2 years
3 years
4 years