HOTSPOT
You upgrade a SharePoint 2010 environment to SharePoint 2013. The new environment includes the
following site collections.
All site collections are backward compatible with SharePoint 2010.
You are preparing to allow site owners to upgrade sites to SharePoint 2013 compatibility mode.
You need to limit the number of sites that can be upgraded concurrently to five or fewer.
Which Windows PowerShell cmdlets should you run? (To answer, select the appropriate cmdlet
from each drop-down list in the answer area.)
Answer: 
Explanation:
* Set-SPContentDatabases
Sets global properties of a SharePoint content database.
* ConcurrentSiteUpgradeSessionLimit
The limit on how many site upgrade session can happen concurrently on this database.
With the pictures http://www.aiotestking.com/microsoft/which-windows-powershell-cmdlets-should-you-run-3/
Correct according to https://technet.microsoft.com/en-us/library/jj219599.aspx
See paragraph “To change the throttle settings for a content database by using Windows PowerShell”.