This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Social & Preventive Medicine
[{'content': 'An investigator is studying the impact seatbelts have on the severity of injuries incurred during a motor vehicle accident. \n\nWhich of the following study designs would be most appropriate for answering this question? \nSelect and explain. \nA. Case series, B. Case-control study, C. Cohort study, D. Clinical trial', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]