An organization has an on-premises Exchange 2010 organization. You plan to implement online email archives in Office 365.
You need to add online archive mailboxes to all of the user accounts.
What should you do? multiple mailboxes.

A.
In the Exchange Admin Center, navigate to the Recipients page and click mailboxes. Select the users who
need the archive mailbox functionality and perform a bulk enable.

B.
In the Exchange Admin Center, navigate to the Recipients page and click users. Select the users who need
the archive mailbox functionality, and perform a bulk enable.

C.
Connect to Exchange Online and run the following Windows PowerShell command: Enable-Mailbox –
UserPrincipalName <UPN> -RemoteArchive

D.
In the Exchange Admin Center, navigate to the Organization page and click mailboxes. Individually select
mailboxes and enable the archive mailbox functionality.

Explanation:

You can access the Recipients page in Exchange admin center (EAC) to bulk-enable archives by selecting
References: https://technet.microsoft.com/en-us/library/jj984357(v=exchg.150).aspx