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
Nalgonda technique is related to? 
Select and explain. 
A. Fluorine, B. Chrlorine, C. Nitrate, D. Nitrites
A: Fluorine
Answer: A: Fluorine 
Explanation: NEERI DEVELOPED A TECHNIQUE FOR REMOVING FLUORIDE BY CHEMICAL DEFLOURIDATION OF WATER CALLED NALGONDA TECHNIQUE. REF. PARK'S TEXTBOOK OF PREVENTIVE AND SOCIAL MEDICAL 21ST EDITION. PAGE NO - 596