You recruit an observational cohort study of adults aged 25-30. You intend to study the association between these adults having been breastfed as a child (exposure) and the adults having graduated high school (outcome), which you collect using surveys among your participants. This is an example of a ________.
1) Cross-sectional, observational cohort study
2) Prospective, observational cohort study
3) Retrospective quasi-experimental controlled study trial
4) Retrospective, observational cohort study
5) None of the above