You have an Exchange Server 2010 Service Pack 1 (SP1) Mailbox server that contains
multiple mailbox databases.
You need to ensure that you are notified when deleted mailboxes are purged from the
server.
What should you do?

A.
Create a new Data Collector Set.

B.
Create a new Event Viewer Subscription.

C.
Attach a new task to the Application event log.

D.
Modify the properties of the mailbox database objects.

Explanation:
http://www.windowsecurity.com/articles/Attaching-Tasks-Event-Viewer-Logs-Events.html