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
Which does not contribute to Enterobillary Fistula - 
Select and explain. 
A. Duodenal ulcer, B. Gall stones, C. Gastric ulcer, D. Carcinoma gall bladder
C: Gastric ulcer
Answer: C: Gastric ulcer 
Explanation: None