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
Internal fistula is most common between gall bladder and: 
Select and explain. 
A. Colon, B. Duodenum Ist pa, C. Jejunum, D. Transverse colon
B: Duodenum Ist pa
Answer: B: Duodenum Ist pa 
Explanation: Answer is B (Duodenum 1st pa)