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': 'Absence of pulp chambers is seen in \nSelect and explain. \nA. Craniofacial dysostosis, B. Dentinogenesis imperfecta, C. Amelogenesis imperfecta, D. Any of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]