You work as the exchange administrator at TestKing.com. The TestKing.com network contains an Exchange Server 2010 Organization. You are responsible for managing an Active Directory Managment Services server named TESTKING-EX01. TestKing.com users currently make use of Outlook Web App （OWA） to access their mailboxes.During the course of day you receive an instruction form the CIO to devise a security solution plan for the organization. Management wants you to ensure that e-mail messages are stored in an encrypted formatand that the administator-defined templates are used to secure messages. What else should you incorporate？（）

A. You should consider incorporating Domain Security into the plan.
B. You should consider incorporating Secure/Multipurpose Internet Mail Extensions （S/MIME） into theplan.
C. You should consider incorporating a legal hold into the plan
D. You should consider incorporating Outlook Protection Rules into the plan.