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: Forensic Medicine
[{'content': "The most 'frequent tooth to be impacted: UPSC 07 \nSelect and explain. \nA. Lower third molar, B. Upper third molar, C. Lower canine, D. Upper premolar", 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. Lower third molar', 'role': 'assistant'}]