Refer to the exhibit. A network administrator is creating a prototype to verify the new WAN design. However, the communication between the two routers cannot be established. Based on the output of the commands, what can be done to solve the problem?

In a serial WAN connection using back-to-back cables, one router must act as DCE and provide clocking. The command output shows the interface is up but line protocol is down, indicating the physical connection exists but synchronization is missing. Configuring 'clock rate' on RA (the DCE device) provides the timing signal needed for the serial link to establish line protocol.