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: Surgery
An empty cavity in the mandible with no lining is
mostly likely to be: 
Select and explain. 
A. Aneurysmal bone cyst, B. Idiopathic bone cavity, C. Dentigerous cyst, D. Keratocyst
B: Idiopathic bone cavity
Answer: B: Idiopathic bone cavity 
Explanation: None