What is the caust of the problem?

Refer to the exhibit. A network administrator configures a new router and enters the copy startup-config running-config on the router. The network administrator powers down the router and sets it up at a remote location. When the router starts, it enter the system configuration dialog as shown. What is the caust of the problem?

A.
The network administrator faled to save the configuration.

B.
The configuration register is set to 0x2100.

C.
The boot system flash command is missing from the configuration.

D.
The configuraiton register is set to 0x2102.

E.
The router is configured with the boot system startup command.