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 change in colour of a traumatized primary incisor\nusually results from all the following except. \nSelect and explain. \nA. Laceration of periodontal fibres, B. Diffusion of biliverdin into the dentinal tubules, C. Development of a heavy layer of secondary dentin, D. Internal resorption of dentin within the crown', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]