Refer to the exhibit. If the switch reboots and all routers have to re-establish OSPF adjacencies, which routers will become the new DR and BDR?

OSPF elections of a DR are based on the following in order of precedence:highest pritority from 1 -255 (0 = never a DR)
highest router ID
highest IP address of a loopback or active interface in the absence of a manually configured router ID. Loopback IP addresses take higher precedence than other interfaces.
In this case routers R4 and R1 have the highest router priority. Between the two, R3 has the higher router ID. Therefore, R4 will become the DR and R1 will become the BDR.