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': 'Direction of case control study? \nSelect and explain. \nA. Direction of study is reverse but time is forward, B. Direction of study is forward and time is also forward, C. Direction of study is forward and time is reverse, D. Direction of study is reverse and time is also reverse', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Direction of study is reverse but time is forward o In case control study i) Direction of study Reverse Time Forward o In coho study i) Direction of study --> Forward ii) Time -Forward", 'role': 'assistant'}]