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