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: Gynaecology & Obstetrics
[{'content': 'The ureter is identified at operation by: \nSelect and explain. \nA. Rich arterial plexus, B. Peristaltic movement, C. Relation to lumber plexus, D. Accompanied by renal vein', 'role': 'user'}, {'content': "Answer: B \nExplanation: At operation, the ureter is recognized by:\n\nIts pale glistening appearance\nBy a fine longitudinal plexus of vessels on its surface\nMore particularly by its peristaltic movement\nBy palpation between finger and thumb as a firm cord which, when escapes, gives a characteristic 'snap'.\n\nThe absence of pulsation does not serve to identify a structure as ureter because veins and obliterated umbilical artery are also non-pulsatile.", 'role': 'assistant'}]