You have a computer that runs Windows 7 Professional. A USB disk is attached to the computer. You needto ensure that you can enable BitLocker To Go on the USB disk. What should you do？（）

A. Enable Encrypting File System （EFS）.
B. Upgrade the computer to Windows 7 Enterprise.
C. Initialize the Trusted Platform Module （TPM） hardware.
D. Obtain a client certificate from an enterprise certification authority （CA）.