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': 'Highest chance of success in renal transplant is seen when the donor is the - \nSelect and explain. \nA. Identical twin, B. Father, C. Mother, D. Sister', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]