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': 'A total of 5000 pts of glaucoma are identified and surveyed by pts. interviews regarding family history of glaucoma. Such a study design is called - \nSelect and explain. \nA. Case series report, B. Case control study, C. Clinical trial, D. Cohort study', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]