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: Surgery
Gold standard test in insulinoma - 
Select and explain. 
A. CT scan, B. Ultrasound, C. MRI, D. Aeriography
B: Ultrasound
Answer: B: Ultrasound 
Explanation: Answer 'b' i.e. Ultrasound "The most impoant examination is intraoperative ultrasound, which can identify a pancreatic tumor in nearly all cases. It is more sensitive than any preoperative test." - CSDT