So many people ______ the meeting had to be put off.为什么不能选A?B呢?

题目

So many people ______ the meeting had to be put off.为什么不能选A?B呢?
A.being absent B.to be absent C.were absen D.had been absent

答案

句意理解 因为很多人缺席会议取消了.
只有现在分词可以表达原因,作原因状语,是它伴随用法的延伸.