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: ENT
Spine of Henle is a: 
Select and explain. 
A. Coical bone, B. Cancellous bone, C. Sclerotic bone, D. Long bone with Haversian system
B: Cancellous bone
Answer: B: Cancellous bone 
Explanation: Spine of henle is a pa of mastoid bone. Mastoid is a spongy or cancellous bone, hence spine of henle is also cancellous.