This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Trauma, Subject name: Surgery
[{'content': 'Which of the following structure is fixed during reimplantation of an amputated digit \nSelect and explain. \nA. Bone, B. Aery, C. Vein, D. Nerve', 'role': 'user'}, {'content': 'Answer: A \nExplanation: .', 'role': 'assistant'}]