What type of software is specifically designed to prevent unauthorized access and altercations in computer systems?

The correct choice focuses on antivirus software, which is specifically designed to detect, prevent, and mitigate unauthorized access and alterations to computer systems caused by malicious threats. Antivirus programs monitor system activities and files, scanning for and quarantining malware that attempts to infiltrate systems. Their primary goal is to safeguard computers by eliminating viruses, worms, trojans, and various other types of malicious software that could compromise system security and integrity.

Antivirus software employs various techniques such as signature-based detection, heuristic analysis, and behavior monitoring to identify potential threats before they can affect system operations. By actively protecting against these threats, antivirus software plays a crucial role in maintaining the security and stability of computer systems against unauthorized access and other security breaches.

In contrast, other types of software listed, such as malware, actually represents the threats that antivirus software aims to eliminate. Operating systems are essential for managing hardware and software resources, but they do not inherently provide protection against unauthorized access unless combined with security features. Productivity software is designed for applications that facilitate tasks and work efficiency, which is unrelated to providing security functions. Thus, antivirus software stands out as the appropriate solution for preventing unauthorized access and alterations in computer systems.