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': 'Silicoflouoride is used in: \nSelect and explain. \nA. Dry feeder system., B. Saturator system., C. Solution feeder system., D. All of the above.', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]