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: Surgery
[{'content': 'The Sagittal split mandibular operation \nSelect and explain. \nA. is a good operation for closing an anterior open bite., B. Has a very low incidence of inferior dental nerve anaesthesia or paraesthesia with a skilled operator., C. Has a lower morbidity when used for pushing back a mandible than an intra oral vertical subsigmoid osteotomy., D. Rarely leads to a non union of the osteotomy site', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]