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': 'The cross linking agent of polysulphide rubber base impression material is \nSelect and explain. \nA. Aromatic sulfonate esters, B. Stannous octate, C. Platinum salt catalyst, D. Lead dioxide', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]