Which of the following is TRUE concerning unnumbered VPN Tunnel Interfaces (VTIs)?

Which of the following is TRUE concerning unnumbered VPN Tunnel Interfaces (VTIs)?

A.
VTIs must be assigned a proxy interface.

B.
VTIs are only supported on SecurePlatform.

C.
VTIs can only be physical, not loopback.

D.
Local IP addresses are not configured, remote IP addresses are configured.