问题补充：
Many young people in the West are expected to leave could be life s most important decision -- marriage -- almost entirely up to luck.
A. as
B. that
C. which
D. what
答案：
A. as
B. that
C. which
(答案→)D. what
解析：句中此处是一个名词性宾语从句，leave 是动词，后面要加宾语。其中that 和which 引导宾语从句的话，要有先行词在连接词的前面。所以应该选D
