The entire population of a given community is examined, and all who are judged to be free from bowel cancer are questioned extensively about their diets. These people then are followed for several years to see whether their eating habits will predict their risk of developing bowel cancer. Which of the following study designs most appropriately characterizes this situation?
A. Cross-sectional study.
B. Case-control study.
C. Prospective cohort study.
D. Historical prospective cohort study.
E. Clinical trial.
F. Community trial.