This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Rectum, Subject name: Surgery
[{'content': 'Flexible sigmoidoscope is .........cm length: \nSelect and explain. \nA. 30 cm, B. 40 cm, C. 60 cm, D. 70 cm', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. (c) 60cmRef: Bailey 26th Edition, Page 1217The image from Bailey demonstrates all the scope lengths:* Proctoscope: 8cm* Per rectal examination: 12cm* Sigmoidoscope (Rigid): 18cm* Sigmoidoscope (Flexible): 60cm* Colonoscope: 160cm', 'role': 'assistant'}]