Refer to the exhibit.

A TFTP server has recently been instated in the Lviv office. The network administrator is located in the Kyiv office and has made a console connection to the Kyiv router. After establishing the connection they are unable to backup the configuration file and iOS of the Kyiv router to the TFTP server. What is the cause of this problem?

A.	The TFTP server has an incorrect subnet mask.
B.	The TFTP server has an incorrect IP address.
C.	The network administrator computer has an incorrect IP address.
D.	The Kyiv router has an incorrect subnet mask.