You need to include a disclaimer to all sent messages in your organization.
Some of the users require message encryption.
How do you make sure that disclaimer can be included in encrypted messages?

A.
Instruct the users to use IRM encryption method only

B.
Instruct the users to use S/MIME encryption method only

C.
Using command New-ExchangeCertificate cmdlet

D.
Using the Set-ExchangeServer cmdlet