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': 'Instructing the patient to say "ah" with short vigorous\nbursts will help in visualizing \nSelect and explain. \nA. Soft palate, B. Posterior vibrating line, C. Anterior vibrating line, D. Junction of hard and soft palate', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]