Which two steps are performed as part of system hardening? (Choose two.)

A.
disable any system services that are not being used

B.
correct files on the system that are not assigned to a valid user

C.
install enough memory to protect against DoS attacks by memory depletion

D.
use a private, non-routable IP address instead of a public, routable IP address

E.
remove the root user account to prevent privilege escalation by normal users