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: Pathology
The most common cause of SVC syndrome is - 
Select and explain. 
A. Thrombosis, B. Extrinsic compression, C. Mediastinal lymphoma, D. Teratoma
B: Extrinsic compression
Answer: B: Extrinsic compression 
Explanation: None