You have a computer named Computer1 that runs Windows XP Professional. Computer1 is a member of a workgroup. You need to prevent all users from encrypting files on Computer1. What should you do?（） 

• A、For all files, deny the Take ownership permission to the Everyone group. 
• B、From the Local Security Policy, modify the Encrypting File System (EFS) properties.
• C、From the Certificates snap-in, delete the recovery agent certificate. 
• D、From the Certificates snap-in, delete all trusted root certification authority (CA) certificates.