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: Anatomy
Sphincterectomy of sphincter of oddi is performed at 
Select and explain. 
A. 3 O'clock position, B. 6 O' clock position, C. 9 O'clock position, D. 11 O'clock position
D: 11 O'clock position
Answer: D: 11 O'clock position 
Explanation: Transduodenal Sphincterectomy This cut is made Superiorly (at 11 O'clock position) for 4 to 5 mm. The sphincter is incised at the 11 O'clock position to avoid injury to the pancreatic duct Ref: Sabiston 20th edition Pgno :1496