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
Graft from sister to brother is - 
Select and explain. 
A. Isograft, B. Allograft, C. Autograft, D. Heterograft
B: Allograft
Answer: B: Allograft 
Explanation: Ans. is 'b' i.e., Allograft