Refer to the exhibit. An engineer must establish eBGP peering between router R3 and router R4. Both routers should use their loopback interfaces as the BGP router ID. Which configuration set accomplis

This configuration correctly establishes eBGP peering by defining the neighbor using its loopback address and setting `update-source Loopback0`, which ensures the BGP TCP session originates from and targets the loopback interface, aligning with the requirement to use loopbacks for peering and as the router ID (by default, the highest loopback IP is chosen as the router ID if not explicitly set).

While `ebgp-multihop` is often necessary for eBGP peering between loopback interfaces that are not directly connected at Layer 3, its omission in option A, which is the correct answer, implies the exhibit or scenario does not require it for successful peering.

Explicitly setting the BGP router ID with `bgp router-id` is an option, but it's redundant if the loopback's IP is already the highest active IP, which is the default selection criterion for the BGP router ID. Option A's approach is simpler and sufficient as the loopback IP would naturally become the router ID.