In a study conducted at the University of Chicago, S. Frankel and colleagues studied middle school students in 10 Illinois communities. Each year for 7 years, they measured the lung function of the children and the levels of coal ash particles in the air in the communities. Was this a cohort study or a case-control study? Was the study prospective, cross-sectional, or retrospective? Pick from the following:
A). This was a retrospective cohort study
B). This was a prospective case-control study
C). This was a retrospective case-control study
D). This was a cross-sectional cohort study
E). This was a prospective cohort study