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 tumor develops from - 
Select and explain. 
A. Enterochromaffin cells, B. Neuroectoderm, C. J cells, D. Goblet cells
A: Enterochromaffin cells
Answer: A: Enterochromaffin cells 
Explanation: Enterochromaffin cells give rise to carcinoid tumors.