The size of the audience, __________ we had expected, was well o

The size of the audience, __________ we had expected, was well over one thousand.
A、whom
B、who
C、as
D、that
【正确答案】：C
【题目解析】：as we expected正如我们所期待的
句意：如我们所料，观众的人数远远超过一千。