This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardio thoracic surgery  , Subject name: Surgery
The commonest anterior mediastinal tumour is 
Select and explain. 
A. Aneurysm of descending aoa, B. Neurogenic tumour, C. Thymoma, D. Bronchogenic cyst
C: Thymoma
Answer: C: Thymoma 
Explanation: Thymomas are the most common anterosuperior mediastinal tumors accounting for 25% of the total.They are commonly associated with myasthenia gravis.Diagnosis and treatment is best achieved by complete thymectomy. Reference:SRB's manual of surgery,5th edition,page no:1127.