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
Which of the following subtype of lung carcinoma produces superior vena cava syndrome: September 2009 
Select and explain. 
A. Small cell carcinoma, B. Adenocarcinoma, C. Anaplastic carcinoma, D. Squamous cell carcinoma
A: Small cell carcinoma
Answer: A: Small cell carcinoma 
Explanation: Ans. A: Small cell carcinoma