Choose the Study Described Below That Likely Has the Greatest

Choose the study described below that likely has the greatest causality, considering the Bradford-Hill criteria as well as the strengths and weaknesses of the study designs.

A) A prevalence study that collected data from a small, rural coal town and found that a higher than average fat intake was associated with an increased prevalence of lung cancer.
B) A randomized control trial that found one day after consuming an extra serving of fruits and vegetables, blood lipid panels improved.
C) A prospective cohort study that found individuals who consumed the highest quartile of snack foods had an increased risk of developing type 2 diabetes compared to the lowest quartile.
D) A correlational study that associated increased dairy consumption with individuals with less physically active lifestyles.