Before she ______ the door, she____what had happened to her computer．

A．walked; noticed                                         B．walked; had noticed

C．walks; has noticed                                    D．had walked; noticed

Before she ______to the door, she ____what had happened to her computer．

A．walked; noticed 　 B．walked; had noticed　

C．walks; has noticed　 　　 D．had walked; noticed