Which three statements about the designated router election in IS-IS are true?

Which three statements about the designated router election in IS-IS are true? (Choose three.)

A.
If the IS-IS DR fails, a new DR is elected.

B.
The IS-IS DR will preempt. If a new router with better priority is added, it just becomes active in
the network.

C.
If there is a tie in DR priority, the router with a higher IP address wins.

D.
If there is a tie in DR priority, the router with a higher MAC address wins.

E.
If the DR fails, the BDR is promoted as the DR.

F.
The DR is optional in a point-to-point network.