How does FortiWeb protect against defacement attacks?

How does FortiWeb protect against defacement attacks?
A . It keeps a complete backup of all files and the database.
B . It keeps hashes of files and periodically compares them to the server.
C . It keeps full copies of all files and directories.
D . It keeps a live duplicate of the database.

Answer: B

Explanation:

The anti-defacement feature examines a web site’s files for changes at specified time intervals. If it detects a change that could indicate a defacement attack,

the FortiWeb appliance can notify you and quickly react by automatically restoring the web site contents to the previous backup.

Reference: https://help.fortinet.com/fweb/551/Content/FortiWeb/fortiweb-admin/anti_defacement.htm