![](https://cos-cdn.shuashuati.com/pipixue-web/2020-1231-2005-12/ti_inject-812ce.png)
After the teacher arrived, the students sat down at their desks.
A.
After the teacher arrived, the students sat down at their desks. - NO CHANGE POSSIBLE
B.
After arriving, the students sat down at their desks.
C.
After arrived, the students sat down at their desks.