You are troubleshooting an OSPF problem where external routes are not showing up in the OSPF database. Which two options a re valid checks that should be performed first to verify proper OSPF operation?（）

A

Are the ASBRs trying to redistribute the external routes into a totally stubby area?

B

Are the ABRs configured with stubby areas?

C

Is the subnets keyword being used with the redistribution command?

D

Is backbone area (area 0) contiguous?

E

Is the CPU utilization of the routers high?