The parents rushed to the school, only ______ that their son had left without a word

The parents rushed to the school, only ______ that their son had left without a word

A.to tell

B.to be told

C.being told

D.having told

答案及解析： B

解析：

考查状语。only to do表示意想不到的结果。逻辑主语The parents与tell为被动关系，故选B。