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
Commonest posterior mediastinal tumour is - 
Select and explain. 
A. Lung cyst, B. Neurofibroma, C. Dermoid, D. Thyroid
B: Neurofibroma
Answer: B: Neurofibroma 
Explanation: None