What should you recommend?

A corporate environment includes Exchange Server 2010. Client computers run Microsoft Outlook 2010.
In the current environment, when users need to recover Outlook items that have been permanently deleted from the Deleted Items folder, administrators must recover the items from a backup of the Exchange Server environment. You have the following requirements:

* Do not require administrators to recover items from the Exchange Server backups.
* Enable online recovery by administrators of permanently deleted items.
* Automatically purge items after a specific period of time.

You need to recommend a solution that meets the requirements.

What should you recommend?

A.
Implement litigation hold.

B.
Create a retention policy.

C.
Create a recovery database.

D.
Configure single item recovery.