Final answer:
A masquerader is an unauthorized individual who penetrates a system to exploit a legitimate user's account by pretending to be that user.
Step-by-step explanation:
An individual who is not authorized to use the computer and who penetrates a system's access controls to exploit a legitimate user's account is known as a masquerader. This term refers to someone who pretends to be an authorized user by obtaining their credentials and then abusing that access. The correct answer to your question is C) masquerader.
A masquerader is an individual who is not authorized to use the computer and who penetrates a system's access controls to exploit a legitimate user's account. Masqueraders pretend to be someone else in order to gain unauthorized access to a system or network. They may use stolen credentials or other deceptive tactics to impersonate a legitimate user and bypass security measures.