1. Match each scenario to the study design it describes: | A. Investigators recruit 150 childhood cancer survivors and 150 individuals who have never been diagnosed with cancer and follow them for 15 years to assess how many develop cancer over the study period B. 200 individuals with diabetes are matched to 200 individuals without diabetes, and both groups are asked about their history of high blood pressure C. Researchers identify a group of 120 smokers and a group of 120 non-smokers from historical medical records and look over the past 20 years to see how many people from each group developed lung cancer during that time period D. Investigators recruit all individuals who developed heart disease from a cohort study and randomly select participants from the same cohort who did not develop heart disease. They use previously collected information on their physical activity levels to examine whether there is an association between physical activity and heart disease Case-cohort study Prospective cohort study Case-control study Retrospective cohort study