Configure OSPF on R1 so the Ethernet link to R2 does not perform a DR/BDR election. Which configuration is required on R1?

The correct command to prevent a DR/BDR election on an OSPF Ethernet link is "ip ospf network point-to-point". By default, Ethernet interfaces operate in OSPF broadcast network type, which triggers DR/BDR elections. Changing the network type to point-to-point on both ends of the link eliminates the need for a DR/BDR, as there are only two routers involved. "ip ospf cost 0" is invalid and would not prevent an election. "hello interval 15" changes the hello timer but doesn't alter the network type. "ip ospf network broadcast" explicitly sets the network type to broadcast, which is the default for Ethernet and would still result in a DR/BDR election.