You have a computer that runs Windows XP Professional. Two users named User1 and User2 share the computer. User1 and User2 encrypt files on the computer. User1 encrypts a file named file1. doc. You need ensure that both User1 and User2 can view the contents of file1. doc. What should you instruct User1 to do?（） 

A、Add the certificate of User2 to file1. doc. 

B、Assign User2 the Full Control NTFS permission on file1. doc. 

C、Copy file1. doc the %systemroot%\documents and settings\all users\ folder.

D、Move file1. doc to the %systemroot%\documents and settings\all users\ folder.&e