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 an example of unilateral fixed space maintainer \nSelect and explain. \nA. Distal Shoe, B. Band and loop, C. Nance arch, D. Crown and loop', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Nance arch is a bilateral fixed space maintainer indicated when there is bilateral tooth loss in the maxilla.', 'role': 'assistant'}]