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: Surgery
A lady present with three day history of epigastric pain radiating to back. Serum amylase levels were observed to be normal while USG abdomen reveals gall bladder stones and an enlarged pancreas. CT scan was done which clinched the diagnosis. Which of the following is the most likely diagnosis 
Select and explain. 
A. Acute Cholecystitis, B. Acute Pancreatitis, C. Acute Appendicitis, D. Acute Peritonitis
B: Acute Pancreatitis
Answer: B: Acute Pancreatitis 
Explanation: Acute pancreatitis pain will radiate to back.Gall bladder calculi is the most common cause. Bailey and Love,26th,1127,1128