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
D cells of Islet of Langerhans of pancreas secrete? 
Select and explain. 
A. Insulin, B. Glucagon, C. Gastrin, D. Somatostatin
D: Somatostatin
Answer: D: Somatostatin 
Explanation: Ans. D SomatostatinRef: Ganong, 25th ed. pg. 154Somatostatin is found in the D cells of pancreatic islets. It inhibits the secretion of insulin, glucagon, and pancreatic polypeptide and may act locally within the pancreatic islets in a paracrine fashion.