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: Surgery
[{'content': 'Features of intestinal obstruction : clinically/investigatiuon by \nSelect and explain. \nA. Abdominal distension, B. Vomiting, C. Fluid level in X-ray >4, D. Localized tenderness', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The diagnosis of dynamic intestinal obstruction is based on the classic quaet of pain, distension, vomiting and absolute constipation. Obstruction may be classified clinically into two types: * small bowel obstruction - high or low; * large bowel obstruction Ref: Bailey & Love&;s Sho Practice of Surgery,E25,Page-1192', 'role': 'assistant'}]