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': 'Most commonly used blinding technique in epidemiological studies \nSelect and explain. \nA. Single blinding, B. Triple blinding, C. Double blinding, D. None of the above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Blinding\n\nThe blinding is used to prevent outcomes from being influenced by the bias. Blinding is a basic tool to prevent concious as well as subconcious bias in the study.\nTo blind a person involved in the study (subject, investigator or observer) is to prevent them from knowing certain information about the study', 'role': 'assistant'}]