Question: We want to know if coffee consumption can be associated with neonatal malformation, so a control case study is designed. We interview a group of women who have had children with malformations and the same in a group of mothers without children with malformations. The interviews will be conducted by two interviewers trained through a previously validated questionnaire. In addition, interviewers ignore whether the interviewee is a case or a control. What kind of bias can we introduce? 
 Options:  <1> Information bias <2> Memory bias <3> Interviewer bias <4> Selection bias <5> Ecological fallacy
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