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
Rigler's triad consists of all except 
Select and explain. 
A. Intestinal obstruction, B. Gas in bile duct, C. Cholangitis, D. Ectopic gallstone
C: Cholangitis
Answer: C: Cholangitis 
Explanation: Gall stone ileus Passage of stone through a spontaneous biliary-enteric fistula leading to a mechanical bowel obstruction Clinical features Rigler's triad : Classic plain abdominal film triad of small bowel obstruction, pneumobilia & ectopic gallstone Ref: Sabiston 20th edition Pgno :1506-1507