You have a computer that runs Windows 7 Professional. A removable drive is attached to the computer.You need to protect data on the removable drive by using BitLocker To Go.  What should you do first? （）

• A、Upgrade the computer to Windows 7 Enterprise.
• B、Install all Windows Updates for Windows 7 Professional.
• C、Issue a digital certificate for the Encrypting File System (EFS).
• D、Select the Encrypt contents to secure data checkbox from the properties on the removable drive.