Who are individuals that exploit computer systems for unauthorized access?

The correct choice is individuals who exploit computer systems for unauthorized access, which directly corresponds to the term "hackers." Hackers are typically associated with the act of breaking into computer systems, networks, or devices with the intent to access information without permission. This unauthorized access can be for various purposes, such as stealing data, inflicting damage, or even just testing security weaknesses.

While phishers, scammers, and network admins are also relevant terms in the realm of cybersecurity, they do not fit this definition. Phishers manipulate individuals into providing sensitive information through deceptive emails or messages but do not necessarily exploit systems directly. Scammers may involve themselves in various deceptive schemes for financial gain, but this does not specifically pertain to hacking computer systems. Network admins, on the other hand, are responsible for maintaining and securing computer networks and do not engage in unauthorized access; instead, they uphold security protocols to protect systems from potential breaches. Thus, hackers are the most accurate representation of those who exploit systems for unauthorized access.