Cohort study

A cohort study determines that there is an inverse association between tomato intake and the risk of developing prostate cancer.  The statistical analysis has included an adjustment for socioeconomic status. Why is this the case?

A. The adjustment allows researchers to say that there is a causation link between tomato intake and prostate cancer.

B. Socioeconomic status was found NOT to be associated with both tomato intake and risk of prostate cancer.

C. Socioeconomic status was found to be associated with both tomato intake and risk of prostate cancer.

D. To ensure that the cohort included participants from all socioeconomic backgrounds.