Your network contains an Active Directory forest that has the site topology shown in the diagram.

You have an Exchange Server 2016 organization. The organization contains three servers. The
servers are configured as shown in the following table:

You have the users described as shown in the following table:

You need to ensure that any email messages sent from User1 to User3 are sent to EX02 first, and
then delivered to EX03. What should you configure?

A.
Site 2 as a hub site

B.
EX02 as an expansion server

C.
the Exchange cost for the site link from Site 2 to Site 3

D.
the Exchange cost for the site link from Site 1 to Site 2

Explanation:
https://technet.microsoft.com/en-us/library/aa998825(v=exchg.150).aspx