which of the following capabilities does RIPv2 improve RIPv1?

With which of the following capabilities does RIPv2 improve RIPv1?

A.
Multicast updates, authentication, variable-length subnet mask (VLSM)

B.
Authentication, VLSM, hop count

C.
Multicast updates, authentication, hop count

D.
Multicast updates, hop count

Explanation:
Explanation

RIPv2 improves on RIPv1 with the ability to use VLSM, with support for route authentication, and with multicasting of route updates. RIPv2 supports CIDR. It still sends updates every 30 seconds and retains the 15-hop limit; it also uses triggered updates. RIPv2 still uses UDP port 520; the RIP process is responsible for checking the version number. It retains the loop-prevention strategies of poison reverse and counting to infinity. On Cisco routers, RIPv2 has the same administrative distance as RIPv1, which is 120. Finally, RIPv2 uses the IP address 224.0.0.9 when multicasting route updates to other RIP routers. As in RIPv1, RIPv2 by default summarizes IP networks at network boundaries. You can disable autosummarization if required.

Cisco Press CCDA 640-864 Official Certification Guide Fourth Edition, Chapter 10