Which statement about application blocking is true?

A.
It blocks access to specific programs.

B.
It blocks access to files with specific extensions.

C.
It blocks access to specific network addresses.

D.
It blocks access to specific network services.

Explanation:
BD
How do you block unknown applications on Cisco Web Security Appliance
If Application Visibility Controls (AVC) are enabled (Under GUI > Security Services > Web Reputation and AntiMalware), then we can block access based on application types like Proxies, File Sharing, Internet utilities.
We can do this under Web Security Manager > Access Policies > ‘Applications’ column <for the required
access policy>.
Source: http://www.cisco.com/c/en/us/support/docs/security/web-security-appliance/118486-technote-wsa-
00.html