【单选题】
You are unable to telnet to a router at address 203.125.12.1 from a workstation with the IP address 203.125.12.23. You suspect that there is a problem with your protocol stack. Which of the following actions is most likely to confirm your diagnosis?()
A、ping 127.0.0.0
B、ping 203.125.12.1
C、telnet 127.0.0.1
D、ping 127.0.0.1
E、tracert 203.125.12.1