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': 'Flexibility of clasp depends on \nSelect and explain. \nA. Length & Cross section of clasp, B. Amount of tempering & Cold working, C. Composition & structure of material, D. All of above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]