what is required for RouterA to exchange routing updates with RouterC?

Refer to the exhibit.

When running EIGRP, what is required for RouterA to exchange routing updates with RouterC?

A.
AS numbers must be changed to match on all the routers

B.
Loopback interfaces must be configured so a DR is elected

C.
The no auto-summary command is needed on Router A and Router C

D.
Router B needs to have two network statements, one for each connected network

Explanation:
Here we required same autonomous system between router A,B,C.Routing updated
always exchange between in same EIGRP EIGRP autonomous system.you can configure more
than one EIGRP autonomous system on the same router. This is typically done at a redistribution
point where two EIGRP autonomous systems are interconnected. Individual router interfaces
should only be included within a single EIGRP autonomous system. Cisco does not recommend
running multiple EIGRP autonomous systems on the same set of interfaces on the router. If
multiple EIGRP autonomous systems are used with multiple points of mutual redistribution, it can
cause discrepancies in the EIGRP topology table if correct filtering is not performed at the
redistribution points. If possible, Cisco recommends you configure only one EIGRP autonomous
system in any single autonomous system.
http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080093f07.shtml