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': 'In case control study of buccal carcinoma ? \nSelect and explain. \nA. CA is commoner in zarda pan users than non users, B. Zarda pan is a cause of buccal CA, C. Zarda pan is associated with buccal CA, D. If use of zarda pan is stopped, number of cases will reduce', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Zarda pan is associased with buccal CA", 'role': 'assistant'}]