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': 'The eruption of mandibular permanent incisors lingual to deciduous dentition, can be perceived by the dentist as: \nSelect and explain. \nA. A pathological finding, B. An arch length discrepancy, C. Normal finding, D. None of the above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The primary teeth may have undergone extensive root resorption and may be held only by soft tissues.\xa0\nIn other instances, the roots may not have undergone normal resorption and the teeth remain solidly in place.\xa0\nThe tooth\xa0buds of succedaneous teeth lie lingual to the primary teeth.\nIt is common for mandibular permanent incisors to erupt lingually, and this\xa0pattern should be considered essentially normal.\nIt is seen both in patients with an obvious arch\xa0length inadequacy and in those with a desirable amount of spacing of the primary incisors.', 'role': 'assistant'}]