Which two statements are true about VPN Monitor on a ScreenOS device?

Which two statements are true about VPN Monitor on a ScreenOS device? (Choose two.)

A.
With a route-based VPN failure, VPN Monitor marks the tunnel interface status as down.

B.
With a policy-based VPN failure, VPN Monitor marks the tunnel interface status as down.

C.
VPN Monitor uses UDP to detect a VPN connection failure.

D.
VPN Monitor uses ICMP to detect a VPN connection failure.