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': 'Rinsing of the impression is important to \nSelect and explain. \nA. Remove excess impression material, B. Remove saliva, C. Hydrate the impression, D. Accelerate the setting', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]