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': 'Which of the following  pontic design is non-mucosal type? \nSelect and explain. \nA. Ridge-lap, B. Modified ridge-lap, C. Sanitary, D. All of the above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]