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
Dental fluorosis not associated with skeletal flourosis are seen at: 
Select and explain. 
A. 1 ppm fluoride, B. 3 ppm fluoride, C. 8 ppm fluoride, D. 10 ppm fluoride
B: 3 ppm fluoride
Answer: B: 3 ppm fluoride 
Explanation: None