This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urology, Subject name: Surgery
[{'content': 'The commonest site of lymphoma in the gastrointestinal system is \nSelect and explain. \nA. Small bowel, B. Stomach, C. Large intestine, D. Oesophagus', 'role': 'user'}, {'content': "Answer: B \nExplanation: Stomach is the commonest site of lymphoma in the gastrointestinal system is Stomach(55%). Helicobacter pylori infection is the causative agent commonly. Other sites are small bowel(30%), colon(10%), ileocaecal region (5%).Reference : page 856 SRB's manual of surgery 5th edition", 'role': 'assistant'}]