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
Carcinoid tumors of lung arises from 
Select and explain. 
A. Type-II pneumocytes, B. Kulchitsky (K) cells, C. Mucus (goblet) cells, D. Clara cells
B: Kulchitsky (K) cells
Answer: B: Kulchitsky (K) cells 
Explanation: . Kulchitsky (K) cells