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
"NALGONDA" technique of defluoridation was developed at: 
Select and explain. 
A. Chennai, B. Nagpur, C. Nalgonda, D. Bangalore
B: Nagpur
Answer: B: Nagpur 
Explanation: None