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
Which of the following is a graft used for reconstruction of ramus and condyle unit, but without growth center in it: 
Select and explain. 
A. Costocondral graft., B. Calvarial graft., C. Sternoclavicular graft., D. Metatarsal head graft.
B: Calvarial graft.
Answer: B: Calvarial graft. 
Explanation: Grafts with growth centre is recommended in children.