HOTSPOT
You install Windows 8.1 Enterprise on a new laptop that will be shipped to a remote user.
You logon to the laptop with the user credentials, map network drives, and configure the
network drives to be always available offline.
Company policy requires that files with a .db1 extension should be excluded from offline file
synchronization.
You need to prevent the user from creating files with a .dbl extension on the mapped drives.
In the Local Group Policy Editor, which setting should you configure? (To answer, select the
appropriate setting in the answer area.)
Answer: 
File screen https://technet.microsoft.com/en-us/library/cc938411.aspx
So based on Nunya’s response, looks like the answer is “Files not cached”
But the answer is correct: enable file screen