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': 'The pontic that should be used in the posterior\nmandibular area is described by the term \nSelect and explain. \nA. Marble contact, B. Modified saddle, C. Saddle, D. Sanitary', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]