An administrator issues the command ping 127.0.0.1 from the command line prompt on a PC. If a reply is received, what does this confirm?（）
- AThe PC has connectivity with a local host.
- BThe PC has connectivity with a Layer 3 device.
- CThe PC has a default gateway correctly configured.
- DThe PC has connectivity up to Layer 5 of the OSI model.
- EThe PC has the TCP/IP protocol stack correctly installed.