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 is not a prefabricated pontic: \nSelect and explain. \nA. Long pin facing., B. Pontip., C. Perel pontic., D. Sanitary facing.', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Example of prefabricated pontics are:\nTrupontic, Long pin facing,\nFlatback, Sanitary facings, Reverse pin facing, Pontips.', 'role': 'assistant'}]