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': 'Premature exfoliation of the primary mandibular\ncanine is the most often the sequelae of which of the following: \nSelect and explain. \nA. Caries, B. Trauma, C. Serial tooth extraction, D. Arch length inadequacy', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]