You want to implement router redundancy in the Company network using the best method  available.  Which protocol specified by RFC 2281 provides network redundancy for IP networks，  ensuring that user traffic immediately and transparently recovers from first-hop failures in network  edge devices or access circuits？（）

• A、 ICMP
• B、 IRDP
• C、 HSRP
• D、 STP
• E、 None of the other alternatives apply