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: Radiology
A 45 year old female presented with progressive lower limb weakness, spasticity, urinary hesitancy and mid dorsal (thoracic) extra axial, dural based, intradural enhancing mass in MRI. What is the diagnosis 
Select and explain. 
A. Intradural lipoma, B. Meningioma, C. Dermoid cyst, D. Neuroepithelial cyst.
B: Meningioma
Answer: B: Meningioma 
Explanation: B i.e. Meningioma