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': 'A deficiency of 5-8 mm usually requires extraction of: \nSelect and explain. \nA. First molars, B. Second premolars, C. First premolars, D. Second molars', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]