It was not until she had arrived home ________ remembered ________ the key in her office．

1. A.
   when she; to leave
2. B.
   and she; leaving
3. C.
   that she; leaving
4. D.
   she; to leave

It was not until she had arrived home ________ remembered ________ the key in her office.

[　　]

A．when, she, to leave

B．and she, leaving

C．that she, leaving

D．she, to leave