单选题 A client who agreed to become an organ donor is pronounced dead. What is the most important factor in selecting a transplant recipient?
A. Blood relationship.
B. Sex and size.
C. Compatible blood and tissue types.
D. Need.

【正确答案】 C

【答案解析】The donor and recipient must have compatible blood and tissue types. They should be fairly close in size and age. When a living donor is considered, it's preferable to have a relative donate the organ. Need is important, but it can't be the critical factor if a compatible donor isn't available.