This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epidemiology, Subject name: Social & Preventive Medicine
[{'content': 'Berkesonian bias refers to - \nSelect and explain. \nA. Bias arsing from different rates of admission to the hospital, B. Bias arising from presence of confounding factors, C. Bias arising from the case not being representative of general population, D. Bias arising from improper selection of cases', 'role': 'user'}, {'content': "Answer: A \nExplanation: This special example of berkesonian bias is termed after Dr. Joseph Berkesonian who recognized this problem. Ref: 25th edition, Park's Textbook of Preventive and Social Medicine, Page no. 81, 82", 'role': 'assistant'}]