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 methods of water fluoridation not depend on electric assistance for water flow \nSelect and explain. \nA. Venturi fluoridator system, B. Solution feeder, C. Dry feeder, D. Saturator', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]