You have an Exchange Server 2010 Service Pack 1 (SP1) Mailbox server named Server1.
You need to ensure that a copy of each email message modified or deleted by a user named
User1 is retained on Server1.
What should you do?

A.
Create a personal tag.

B.
Enable single item recovery.

C.
Enable message tracking

D.
Enable a litigation hold

E.
Create a retention policy

F.
Create a journal rule

Explanation:
http://technet.microsoft.com/en-us/library/ee861123.aspx