Refer to the Graphic

Refer to the graphic. The host has a problem establishing a telnet connection with the router attached to interface G0/0/0. Which of the following steps can be used to help the administrator identify the problem? (Choose two)

A) Check whether the host has configured the gateway IP address.
B) Check whether the switch has configured the gateway IP address.
C) Use the ping tool to check connectivity between host and router.
D) Check the telnet server configuration is right on the router.