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
HC1 secretion in gastric phase is increase by 
Select and explain. 
A. Pepsinogen, B. CCK, C. Gastrin, D. Secretin
C: Gastrin
Answer: C: Gastrin 
Explanation: Acid in the antrum inhibits gastrin secretion, paly by a direct action on G cells and paly by release of somatostatin, a relatively potent inhibitor of gastrin secretion. Th effect of acid is the basis of a negative feedback loop regulating gastrin secretion. Increased secretion of the hormone increases acid secretion, but the acid then feeds back to inhibit fuher gastrin secretion. REFERENNCE ; GANONGS REVIEW OF MEDICAL PHYSIOLOGY 24TH EDITION