Final answer:
The correct PowerShell cmdlet to increase the BranchCache storage space is Add-BCDataCacheExtension. This cmdlet allows you to specify additional disk space to the BranchCache, which helps improve access times and reduce bandwidth usage, the correct option is C).
Step-by-step explanation:
The PowerShell cmdlet used to increase the BranchCache storage space is Add-BCDataCacheExtension.
To adjust the storage space, you would typically first check the current cache size using Get-BCCache, then increase it with Add-BCDataCacheExtension by specifying the amount of disk space to add.
This cmdlet is a part of the BranchCache PowerShell module which is used to manage the BranchCache feature that caches network content from a central location on local volumes to decrease bandwidth usage and improve access times for content on remote servers.