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': 'Confounding factors can be eliminated by all except \nSelect and explain. \nA. Matching, B. Randomization, C. Ethical consideration, D. Stratification', 'role': 'user'}, {'content': 'Answer: C \nExplanation: A confounding factor is defined as one which is associated with both exposure and disease and is distributed unequally in study and control groups. (refer pgno:72 park 23 rd edition)', 'role': 'assistant'}]