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
Most common lung cancer associated with ectopic ACTH is 
Select and explain. 
A. Small cell cancer, B. Carcinoid, C. Squamous cell carcinoma, D. Adenocarcinoma
B: Carcinoid
Answer: B: Carcinoid 
Explanation: Ectopic ACTH production is most commonly associated with lung carcinoid.