Which statement about the Cisco IOS Zone-Based Policy Firewall is true?

Which statement about the Cisco IOS Zone-Based Policy Firewall is true?

A.
Only virtual interfaces can be added to a Cisco IOS Zone-Based Policy Firewall zone.

B.
A Cisco IOS Zone-Based Policy Firewall zone is a set of VLANs that share a certain trust
level.

C.
Cisco IOS Zone-Based Policy Firewall policies are not unidirectional.

D.
The Cisco IOS Zone-Based Policy Firewall applies firewall policies to traffic traversing
zones.