You need to install Windows 7 Professional on all Windows 7 Ultimate portable computers

Your company network includes portable computers that have Windows 7 Ultimate and Windows 7
Professional installed.
You want to standardize all portable computers to Windows 7 Professional for Key Manager Server
(KMS) licensing purposes.
You need to install Windows 7 Professional on all Windows 7 Ultimate portable computers.
What should you do?

A.
Launch Windows Update

B.
Perform a clean installation over the existing system partitions.

C.
Perform a clean installation on non-system partitions.

D.
Supply the Windows 7 Professional KMS key.

E.
Launch Windows Anytime Upgrade.

Explanation:
Think that this is right don’t think it can be done