A.Put NONE in /etc/telnet.allowB.Put a line ’ALL:ALL’in /etc/hosts.denyC.Comment the telnet entry in /etc/inittabD.Comment the telnet entry in /etc/xinetD.conf
A.once a day from cronB.once a week from cronC.after installing a new kernelD.after installing a new module
A.diffB.differentC.rpm –vD.makeE.patch