A.The total end-to-end delay
B.The variations of delay.
C.The delay caused by placing the bits on the wire.
D.The time it takes for the bits to transit the physical media.

A.A priority of 0 will prevent a router from becoming a DIS.
B.If the DIS becomes unavailable the backup DIS is promoted to DIS.
C.Adding a router with a higher priority than the current DIS will result in the new router becoming DIS.
D.Separate L1 and L2 election processes are held on a brodcast network.
E.L1 routers on a broadcast network only establish adjacencies with the DIS.
F.If there is a tie based on priority，the router whose attached interface has the lowest MAC address becomes the DIS.