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': 'Facial plane is formed by \nSelect and explain. \nA. Sella gnathion, B. Sella nasion, C. Nasion pogonion, D. Nasion subspinale', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]