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': 'Bias is defind as? \nSelect and explain. \nA. Spurious association between two variables, B. A quantified relationship between exposure and disease, C. Systematic error in determination of association between exposure and disease, D. Statistical technique used to evaluate the effect of a treatment by comparing treated and non treated', 'role': 'user'}, {'content': "Answer: C \nExplanation: Bias is any systemic error in the determination of the association between exposure and diseases. The relative risk estimate may increase or decrease as a result of the bias. It reflects some type of no compatibility between the study and control groups. Ref: 25th edition, Park's Textbook of Preventive and Social Medicine, Page no. 81", 'role': 'assistant'}]