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': 'Alginates are made dust free by adding: \nSelect and explain. \nA. Glycol, B. Glycerol, C. Glutamic acid, D. alcohol', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]