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: Radiology
Which of the following has a radiolucency closest to the dentin: 
Select and explain. 
A. ZOE, B. Calcium hydroxide, C. Silicophosphate, D. Gutta percha
C: Silicophosphate
Answer: C: Silicophosphate 
Explanation: None