For survey of immunization by WHO age group selected is ?
High-Yield Explanation
Ans. is 'a' i.e., 12 - 23 months In the Expanded programme on Immunization (EPI) cluster technique, a simplified cluster sampling method is used. It is based on ranodm selection of 210 children who are 12-23 months of age. These patients are selected in 30 clusters of 7 children each to estimate immunization coverage levels.