A. Rename the URL to a more obscure name, whitelist all corporate IP blocks, and require two-factor authentication.
B. Change the default password, whitelist specific source IP addresses, and require two-factor authentication.
C. Whitelist all corporate IP blocks, require an alphanumeric passphrase for the default password, and require two-factor authentication.
D. Change the username and default password, whitelist specific source IP addresses, and require two-factor authentication.