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
Endoscopy is useful in diagnosis of peptic ulcer in following sutuations except - 
Select and explain. 
A. Post bulbar ulcer, B. Stomal ulcers, C. Giant duodenal ulcer, D. Duodenal erosion
C: Giant duodenal ulcer
Answer: C: Giant duodenal ulcer 
Explanation: None