You need to identify which users have the largest mailboxes on the server

You have an Exchange Server 2010 Mailbox server. You need to identify which users have
the largest mailboxes on the server.
What should you do?

A.
Run the Get-MailBoxStatistics cmdlet.

B.
Run the Get-StoreUsageStatistics cmdlet.

C.
Add the MSExchangeIS Client performance counters to the Performance Monitor.

D.
Add the MSExchangeIS Mailbox performance counters to the Performance Monitor.