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
Desensitizing paste has 
Select and explain. 
A. NaCl, B. KnO3 (Potassium Nitrate), C. HnO3, D. KCl
B: KnO3 (Potassium Nitrate)
Answer: B: KnO3 (Potassium Nitrate) 
Explanation: None