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': 'Amelogenesisimperfecta is due to? \nSelect and explain. \nA. ENAM, B. MSX-1, C. DSPP, D. PAX-9', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]