This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Medicine
The triad of diabetes, gallstones and steatorrhea is associated with - 
Select and explain. 
A. Gastrinoma, B. Somatostatinoma, C. VlPoma, D. Glucagonoma
B: Somatostatinoma
Answer: B: Somatostatinoma 
Explanation: The somatostatinoma syndrome is due to an neuroendocrine tumour (NET) that secretes excessive amounts of somatostatin, which causes a distinct syndrome characterized by diabetes mellitus, gallbladder disease, diarrhea, and steatorrhea. The mean age is 51 years. Somatostatinomas occur primarily in the pancreas and small intestine. Reference : page 570 Harrison's Principles of Internal Medicine 19th edition