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': 'Underdeveloped maxilla is seen in : \nSelect and explain. \nA. Treacher Collins syndrome, B. Pierre Robin syndrome, C. Craniofacial dysostosis, D. Both 1 and 2', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]