This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nutrition and health, Subject name: Social & Preventive Medicine
[{'content': 'Process of deflouridation of water is - \nSelect and explain. \nA. Nalgonda technique, B. NINH, C. Sand filter, D. Parboiling', 'role': 'user'}, {'content': "Answer: A \nExplanation: The National Environmental Engineering Research Institute,Nagpur developed a technique for removing flouride by chemical treatment.It is called Nalgonda technique for deflourination of water.REF.PARK'S TEXTBOOK OF PREVENTIVE AND SOCIAL MEDICINE.Editon-21.Page no.-596", 'role': 'assistant'}]