What is the fastest way to back up your Security Gateway R77 configuration, including routing and network configuration files?

Your primary Security Management Server runs on GAiA. What is the fastest way to back up your
Security Gateway R77 configuration, including routing and network configuration files?

A.
Copying the directories $FWDIR/conf and $FWDIR/lib to another location.

B.
Use the command snapshot.

C.
Using the command upgrade_export.

D.
Using the native GAiA back up utility from command line or in the Web-based user interface.