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: Physiology
Motilin is secreted by cells ina) Stomachb) Duodenumc) Pancreasd)  Liver 
Select and explain. 
A. ac, B. ab, C. ad, D. bc
B: ab
Answer: B: ab 
Explanation: Motilin secreted by
-        M cells of duodenal mucosa (Main)
-        Stomach
 
-        Colon