Mary quickly closed the door of her room _______ her father could reach it to keep him out

1. A.
   before
2. B.
   when
3. C.
   as
4. D.
   while

.

 Mary quickly closed the door of her room _______ her father could reach it to keep him out.

  A. before            B. when                  C. as                     D. while

Mary quickly closed the door of her room _______ her father could reach it to keep him out.

A. before　　　 B. when　　　　　 C. as　　　　　　　 D. while

 Mary quickly closed the door of her room _______ her father could reach it to keep him out.

A. before                  B. when          C. as             D. while

.
Mary quickly closed the door of her room _______ her father could reach it to keep him out.