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
The most effective caustic that may be used locally in the treatment of hypersensitive dentin in the molars is: 
Select and explain. 
A. Alcohol, B. Chlorhexidine, C. Trichloro acetic acid, D. Silver nitrate
D: Silver nitrate
Answer: D: Silver nitrate 
Explanation: None