The process of making certain that an entity (operating system, application, etc.) is as secure as it
can be is known as:

A.
Stabilizing

B.
Reinforcing

C.
Hardening

D.
Toughening

Explanation:
Hardening is the process of securing a system by reducing its surface of vulnerability. Reducing
the surface of vulnerability typically includes removing unnecessary functions and features,
removing unnecessary usernames or logins and disabling unnecessary services.