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: Radiology
A patient complains of epigastric pain, radiating to back off and on. The investigation of choice is – 
Select and explain. 
A. MRI, B. CT scan, C. USG, D. Radio nucleotide scan
B: CT scan
Answer: B: CT scan 
Explanation: Epigastric pain radiating to back suggests the diagnosis of acute pancreatitis. CECT is the investigation of choice for pancreatitis.