This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Physiology
Most potent stimulus for secretin 
Select and explain. 
A. Acid chyme, B. Dilation of intestine, C. Fat, D. Protein
A: Acid chyme
Answer: A: Acid chyme 
Explanation: Acidic chyme is the most potent stimulus for secretin Ref: guyton and hall textbook of medical physiology 12 edition page number:416,417,418