A.in front of
在...的前面
A crowd gathered in front of the building.大楼前围了一大群人.
in the front of
在...的最前部
B.in advance of
在...的前面
He walked in advance of his wife.他走在他妻子的前面.
C.before 介词
在...以前
Only two days remained before the examination.考前只剩下两天了.
(指顺序、重要性等)在...之前,先于
Your name comes before mine.你的名字在我之前.
Pride comes before a fall.骄必败.
由...考虑中
We will put the matter before the committee.我将把此事提交委员会考虑.
在...前面;在...面前
She said she had never spoken before an audience.她说她从未在大庭广众讲演过.
D.ahead of 词组
在...之前
ahead of time
提前;提早
be ahead of
超前
你自己比较一下.我觉得选D.