Routers R1 and R2, currently EIGRP neighbors over their Fa0/0 interfaces (respectively),both use EIGRP authentication. Tuesday at 8 p.m. the neighborship fails. Which of the following wo uld not be useful when investigating whether authenticationhad anything to do with the failure?()
A. debug eigrp packet
B. show key chain
C. show ip eigrp neighbor failure
D. show clock