HOTSPOT
Your network contains one Active Directory forest named contoso.com. The forest contains the
domain controllers configured as shown in the following table.
You perform the following actions:
Create a file named File1.txt in the SYSVOL folder on DC1.
Create a user named User1 on DC4.
You need to identify on which domain controller or controllers a copy of each object is stored.
What should you identify? To answer, select the appropriate options in the answer area.
Answer: 
Explanation:
* SYSVOL is simply a folder which resides on each and every domain controller within the domain. It
contains the domains public files that need to be accessed by clients and kept synchronised between
domain controllers.
Here File1.text will be stored on both domain controllers in contoso.com (DC1, DC2 and DC3).
* User1 is stored on DC4 and on the global catalog servers DC1 and DC2, but not on DC5 and DC6 as
they are on another site.How Active Directory Replication Topology Works
https://technet.microsoft.com/en-us/library/cc755994(v=ws.10).aspx
I Think that the question behind this is “What is the scope of replication” for file1.txt and User1. Ok for file1 but for User1, the user object will be replicated on the site1 and on also on DC5 and DC6.
They are two separate domains, so sites wouldn’t over lap. The GC’s would have a copy of the user account.
DC4, DC5 & DC6 are all in the na.contoso.com domain so even though they are in different sites you’d think there would have to be sitelinks between the 2 so the User would replicate.
So it DC3- File1.txt
and DC 4,5,6 – User1
Answer given is correct
A global catalog is a domain controller that stores a copy of all Active Directory objects in a forest. The global catalog stores a full copy of all objects in the directory for its host domain and a partial copy of all objects for all other domains in the forest,
https://technet.microsoft.com/en-gb/library/cc736934(v=ws.10).aspx
Scrap last point!
So it DC3- File1.txt
and DC 4,5,6 – User1
Answer reference here.
http://www.aiotestking.com/microsoft/what-should-you-identify-101/
I thought if it is not GC is not going to replicate it another DC.
GC replication between DCs in different domains in same forest. DCs in same domain should replicate.