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': 'Which of the following is used as a thickening agent in dentrifices? \nSelect and explain. \nA. Calcium carbonate, calcium phosphate and calcium sulphate, B. Sodium bicarbonate and aluminium oxide, C. Sodium lauryl sulphate and sodium lauryl succinate, D. Carboxymethyl cellulose and alginate amylase', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]