This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Aerial disorders, Subject name: Surgery
[{'content': 'Abdominal aoic aneurysm is operated when the size is more than: \nSelect and explain. \nA. 35 mm, B. 45 mm, C. 55 mm, D. 65 mm', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Cut off diameter ( an Indication of surgery)- 1. Descending thoracic aoa aneurysm >6.5 cm 2. Abdominal aoic aneurysm & Ascending aoic aneurysm > 5.5 cm 3. Iliac aery aneurysm > 3.5 cm 4. Popliteal & femoral Aery Aneurysm > 2 cm', 'role': 'assistant'}]