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: Medicine
Lung to lung metastasis is seen in 
Select and explain. 
A. Adenocarcinoma of lung, B. Squamous cell carcinoma, C. Small cell carcinoma, D. Neuroendocrine tumor of lung
A: Adenocarcinoma of lung
Answer: A: Adenocarcinoma of lung 
Explanation: None