An administrator issues the command "ping 127.0.0.1" from the command line prompt on a PC host named PC1. If an ICMP reply is received, what does this confirm? A. The PC host PC1 has connectivity with a local host B. The PC host PC1 has connectivity with a Layer 3 device C. The PC host PC1 has a default gateway correctly configured D. The PC host PC1 has connectivity up to Layer 5 of the OSI model E. The PC host PC1 has the TCP/IP protocol stack correctly installed