Do you know a boy ______ sister is a nurse in a hospital?

问题描述:

Do you know a boy ______ sister is a nurse in a hospital?
A.who    B.that    C.whom    D.

选D.
你认识那个他姐姐在医院当护士的那个男孩吗?
whose在这里是指“男孩的”,定语从句的关系代词.