A Scientist Is Interested in the Relationship Between Diet and Breast

A scientist is interested in the relationship between diet and breast cancer and decides to do a case-control study.He is able to find a group of women who have breast cancer and collects dietary intake information from them.What is the next step in this study?

A) The scientist must assemble a group of healthy women (the controls) who are the same age and ethnicity as the women who have breast cancer (the cases) .
B) The scientist must assemble a group of healthy women (the cases) who are the same age and ethnicity as the women who have breast cancer (the controls) .
C) The scientist must assemble a group of healthy women (the controls) ,measure their dietary intake,and tract them for several years to see if they develop breast cancer.
D) The scientist must assemble a group of women who have breast cancer from another country,measure their dietary intake,and see if it differs from the first group of women.