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
[{'content': "Which medium of storage for avulsed tooth is best for\nprolonged extra oral periods? \nSelect and explain. \nA. Hank's Balanced salt solution, B. Milk, C. Distilled water, D. Saliva", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]