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': 'Caridex remains stable for how much time after mixing its constituents ? \nSelect and explain. \nA. 20 minutes, B. 30 minutes, C. 60 minutes, D. 120 minutes', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Chemical softening of carious dentin \x96gentle excavation (Caridex and Carisolv)', 'role': 'assistant'}]