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': 'All of the following factors influence the flexibility of\nthe clasp EXCEPT \nSelect and explain. \nA. Diameter of the clasp are, B. Length of the clasp, C. Material of the clasp, D. Tooth on which the clasp rests', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]