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
[{'content': 'Coffee bean appearance is seen with: \nSelect and explain. \nA. Testicular torsion, B. Volvulus, C. Meconium ileus, D. Ileal atresia', 'role': 'user'}, {'content': "Answer: B \nExplanation: Sigmoid volvulus produces a characteristic bent inner tube or coffee bean appearance, with the convexity of the loop lying in the right upper quadrant. Gastrografin enema shows a narrowing at the site of the volvulus and a pathognomonic bird's beak Ref: Schwaz's principle of surgery 9th edition, chapter 29.", 'role': 'assistant'}]