You need to ensure that users in fabrikam.com can find their mailboxes automatically

A company named Contoso, Ltd., has an Exchange Server 2013 organization. The primary SMTP
suffix for all users is contoso.com.
A company named Fabrikam, Inc., has an Exchange Server 2010 organization. The primary SMTP
suffix for all users is fabrikam.com.
The users in both organizations access their email by using Microsoft Outlook 2010 and Outlook
Anywhere. All of the users work from domain-joined client computers that connect to the internal
network.
Contoso acquires Fabrikam.
You establish a cross-forest trust between the Contoso forest and the Fabrikam forest.
In fabrikam.com, you create a user named User1. In contoso.com, you create a linked mailbox for
User1 and you set the primary SMTP address to [email protected].
User1 reports that Outlook 2010 fails to configure his mail profile automatically. User1 can manually
configure his profile and connect to his mailbox.
You need to ensure that users in fabrikam.com can find their mailboxes automatically.
What should you do in contoso.com?

A.
Create a DNS record named autodiscover.fabrikam.com. Point the record to the virtual IP address
of the Client Access servers.

B.
Modify the ExternalURL of the Autodiscover virtual directory on the Exchange Servers 2013
servers.

C.
Modify the Autodiscover Service Connection Point (SCP).

D.
Run the Export-AutoDiscoverConfig cmdlet on an Exchange Server 2013 server.

Explanation:
You can configure Microsoft Exchange services, such as the Availability service, for the Autodiscover
service on a Microsoft Exchange Server 2010 Client Access server.
When you enable Outlook Anywhere, you must also configure external client access to Microsoft
Exchange services for the Autodiscover service. Other external URLS you must configure include the
URLs for the Availability service, Exchange Web Services, Unified Messaging (UM), and the offline
address book.