Which NGX feature or command allows Security Administrators to revert to earlier versions of the Security Policy without changing object configurations?

Which NGX feature or command allows Security Administrators to revert to earlier versions of the Security Policy without changing object configurations?

A.
upgrade_export/upgrade_import

B.
Policy Package management

C.
fwm dbexport/fwm dbimport

D.
cpconfig

E.
Database Revision Control