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': 'Which of the following is a graft used for reconstruction of ramus and condyle unit, but without growth center in it: \nSelect and explain. \nA. Costocondral graft., B. Calvarial graft., C. Sternoclavicular graft., D. Metatarsal head graft.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Grafts with growth centre is recommended in children.', 'role': 'assistant'}]