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
When pH of stomach lumen falls below 4, antrum of the stomach releases a peptide that acts locally to inhibit gastrim release. This peptide is 
Select and explain. 
A. Intrinsic factor, B. Secretin, C. Somatostatin, D. Gastrin
C: Somatostatin
Answer: C: Somatostatin 
Explanation: Somatostatin and Prostaglandins inhibits gastrin release.