HOTSPOT
Your network contains one Active Directory forest named contoso.com and one Active Directory
forest named adatum.com. Each forest contains a single domain.
You have the domain controllers configured as shown in the following table.
You perform the following three actions:
Create a user named User1 on DC3.
Create a file named File1.txt in the SYSVOL folder on DC1.
Create a Group Policy object (GPO) named GPO1 on DC1 and link GPO1 to Site2.
You need to identify on which domain controller or controllers each object is stored.
What should you identify? To answer, select the appropriate options in the answer area.
Answer: 
Explanation:
Understanding the Global Catalog
https://technet.microsoft.com/en-us/library/cc730749.aspx
Shouldn’t it be:
x-x
x-x
-x-
-x-
No sites or trusts setup between forests , so is all seperate
File1 User1 GPo1
Dc1 Y N Y
Dc2 Y N Y
Dc3 N Y N
Dc4 N Y N
Agree, no trust configured between both forests, User, file and GPO will remain within its home domain
This one is really easy, some of you apparently don’t even know what GC’s are or GPO’s…
In this example, you have two forests. There is only one GC per forest by default. In this example, you have two forests, so you have two GC’s. The purpose of global catalogs is as follows: Store backup of AD objects in the forest. Store complete replicas of the domain in the forest.
The question states:
“You need to identify on which domain controller or controllers each object is stored.”
So now, knowing what you know about Global Catlogs, you’ll know that if you create an file, user, or other object on one DC, it will be replicated automatically to the DC which hosts the Global Catalog.
This part of the quesiton:
“– Create a Group Policy object (GPO) named GPO1 on DC1 and link GPO1 to
Site2.” Ok, yay. Good for the GPO. By linking the GPO you are allowing that GPO to set permissions to the schema. Has nothing to do with STORING. Also, the GC in the contoso forest will not replicate to the adatum forest GC just because you link the GPO to it…because they are two different forests.
The correct answer is:
File 1 > DC 1 & 2
User 1 > DC 3 & 4
GPO 1 > DC 1 & 2