A doctoral student wishes to conduct his research on the association between video game playing between ages 6-10 with metabolic syndrome in young adults aged 20-25 years old.

A doctoral student wishes to conduct his research on the association between video game playing between ages 6-10 with metabolic syndrome in young adults aged 20-25 years old. He only has two years to complete the project. Note that the prevalence of metabolic syndrome among US. young adults is "’ 4%, making it a rare disease. a. (1 point) What is the most appropriate study design for this research question and situation? i. Case report/case series ii. Cross-sectional study using ecologic data (ecologic study) iii. Cross-sectional study iv. Case-control study v. Prospective cohort study vi. Retrospective cohort study vii. Randomized trial b. (2 points) Justify your answer above.