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: Dental
[{'content': 'According to Hierarchy of Evidence for Scientific Literature, Randomized control trials are \nSelect and explain. \nA. Level I Evidence, B. Level II Evidence, C. Level III Evidence, D. Level IV Evidence', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]