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
Dentin is composed of 
Select and explain. 
A. 70% inorganic, B. 30% inorganic, C. 50% inorganic, D. 96% inorganic
A: 70% inorganic
Answer: A: 70% inorganic 
Explanation: None