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
Most potent stimulus for secretin secretion is 
Select and explain. 
A. Distension of stomach, B. Bile in duodenum, C. Protein in duodenum, D. Fatty food in duodenum
C: Protein in duodenum
Answer: C: Protein in duodenum 
Explanation: Protein / acid in duodenum is the most potent stimulus for secretion of secretin.