Refer to the exhibit.

Router RTA is the hub router for routers RTB and RTC. The Frame
Relay network is configured with EIGRP, and the entire network is in autonomous system 1.
However, router RTB and RTC are not receiving each other’s routes. What is the solution?

A.
Check and change the access lists on router RTA.

B.
Configure the auto summary command under router eigrp 1 on router RTA.

C.
Configure subinterfaces on the spoke routers and assign different IP address subnets for
each subinterface.

D.
Issue the no ip split horizon command on router RTA.

E.
Issue the no ip split horizon eigrp 1 command on router RTA.

F.
Configure a distribute list on router RTA that allows it to advertise all routes to the spoke
routers.

Explanation:
Split horizon controls the sending of EIGRP update and query packets. When split horizon is
enabled on an interface, these packets are not sent for destinations for which this interface is
the next hop. This reduces the possibility of routing loops.
By default, split horizon is enabled on all interfaces.

Split horizon blocks route information from being advertised by a router out of any interface
from which that information originated. This behavior usually optimizes communications
among multiple routing devices, particularly when links are broken. However, with
nonbroadcast networks (such as Frame Relay and SMDS), situations can arise for which
this behavior is less than ideal. For these situations, you may want to disable split horizon.
In this example, routes received by RTB and RTC are not being sent back out the same
serial interface on RTA, so they are not receiving each other’s routes. Disabling Split
horizons on interface S0/0 on RTA will fix this issue.