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: Surgery
[{'content': 'The most frequent tooth to be impacted is : \nSelect and explain. \nA. Lower third molar, B. Lower canine, C. Upper third molar, D. Upper premolar', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Impacted tooth :\n\nIs the tooth that has failed to erupt completely or partially to its correct position in the dental arch and its eruption potential has been lost.\n\nOrder of frequency :\n\nMandibular 3rd molar (i.e. Lower 3rd molar).\nMaxillary 3rd molar (Upper 3rd molar).\nMaxillary canine.', 'role': 'assistant'}]