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': 'A refiner for a complete denture is contraindicated when \nSelect and explain. \nA. There is resorption of the ridge, B. The denture contains a broken tooth, C. Centric occlusion and centric relation do not coincide, D. There is excessive over-closure of the vertical dimension', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]