What should be done prior to backing up an IOS image to a TFTP server?（）
A. Make sure that the server can be reached across the network.
B. Check the authentication for TFTP access to the server is set.
C. Assure that the network server as adequate space for the IOS image.
D. Verify file naming and path requirements.
E. Make sure that the server can store binary files.
F. Adjust the TCP window size to speed up the transfer.
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