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
Features of intestinal obstruction : clinically/investigatiuon by 
Select and explain. 
A. Abdominal distension, B. Vomiting, C. Fluid level in X-ray >4, D. Localized tenderness
A: Abdominal distension
Answer: A: Abdominal distension 
Explanation: 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