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
Which medium of storage for avulsed tooth is best for
prolonged extra oral periods? 
Select and explain. 
A. Hank's Balanced salt solution, B. Milk, C. Distilled water, D. Saliva
A: Hank's Balanced salt solution
Answer: A: Hank's Balanced salt solution 
Explanation: None