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: Pathology
[{'content': 'Yellow or green pigmentation of teeth is seen in: \nSelect and explain. \nA. Erythroblastosis fetalis, B. Porphyria, C. Internal resorption, D. Nasmyth membrane', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]