Which of the following Windows features should the technician check to ensure that there is not an explicit rule disallowing access to this location?

Windows 7 has notified a user that it has blocked access to the following address in Internet Explorer: ftp://ftp.microsoft.com:21. Which of the following Windows features should the technician check to ensure that there is not an explicit rule disallowing access to this location?

A.
Windows Bitlocker

B.
Windows BranchCache

C.
Windows User Account Control

D.
Windows Firewall