This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Transplantation, Subject name: Surgery
What is a xenograft: 
Select and explain. 
A. Transplantation of organs from a 1st degree relative, B. Transplantation of organs from unrelated donor, C. Transplantation of tissues from self, D. Transplantation of living tissues/organs from one species to another
D: Transplantation of living tissues/organs from one species to another
Answer: D: Transplantation of living tissues/organs from one species to another 
Explanation: Ans. (d) Transplantation of living tissues/organs fromone species to anotherRef: Bailey & Love 26th ed./833* Xenotransplantation is the transplantation of living cells, tissues or organs from one species to another. Such cells, tissues or organs are called xenografts or xenotransplants.* In contrast, the term allotransplantation refers to a same-species transplant. Human xenotransplantation offers a potential treatment for end-stage organ failure, a significant health problem in parts of the industrialized world.