Which of the following configuration is correct?

NGFW_A and NGFW_B, NGFW_A and NGFW_C configure static routes respectively. NGFW_A -> NGFW_B is the primary link, and NGFW_A -> NGFW_C is the backup link. It is required that the traffic can be quickly switched to the backup link when the primary link fails; the traffic can be switched to the primary chromium road after the primary link is restored.

Which of the following configuration is correct? (Multiple Choice)

A . [USG_A] bfd
[USG_A] bfd ab bind peer-ip 10.1.1.2
[USG_A-bfd-session-ab] discriminator local 10
[USG_A-bfd-session-ab] discriminator remote 20
[USG_A-bfd-session-ab] commit
[USG_A] ip route-static 0.0.0.0 0 10.1.1.2 track bfd-session ab
[USG_A] ip route-static 0.0.0.0 0 20.1.1.2 preference 100
B. [USG_A] bfd
[USG_A] bfd ab bind peer-ip 10.1.1.2
[USG_A-bfd-session-ab] discriminator local 10
[USG_A-bfd-session-ab] discriminator remote 20
[USG_A-bfd-session-ab] commit
[USG_A] ip route-static 0.0.0.0 0 10.1.1.2
[USG_A] ip route-static 0.0.0.0 0 20.1.1.2 preference 100 track bfd-session ab
C. [USG_B] bfd
[BSG_B] bfd ab bind peer-ip 10.1.1.1
[USG_B-bfd-session-ab] discriminator local 20
[USG_B-bfd-session-ab] discriminator remote 10
[USG_B-bfd-session-ab] commit
D. [USG_B] bfd
[BSG_B] bfd ab bind peer-ip 10.1.1.1
[USG_B-bfd-session-ab] discriminator local 10
[USG_B-bfd-session-ab] discriminator remote 20
[USG_B-bfd-session-ab] commit