Please, choose only 1 from the following bias examples in different studies, and discuss how to minimize this particular type of bias in this particular context.  (2 marks)

a)    Interviewer bias in a cross-sectional study on the eating habits of pregnant mothers

b)    Diagnostic bias in a cohort study on breast cancer incidence among users and non-users of contraception pills

c)    Selection bias in a case-control study on the association between second-hand smoke and ischemic heart disease