Creating which of the following is how a hacker can insure his ability to return to the hacked system at will?A. rootsec

B.
checksum

C.
CRC

D.
backdoors

E.
None of the choices.

Explanation:
A backdoor refers to a generally undocumented means of getting into a system, mostly for programming and
maintenance/troubleshooting needs. Most real world programs have backdoors. Creating backdoors is how a
hacker can insure his ability to return to the hacked system at will.