When examining the security configuration of an operating system, an IS auditor should review:

Reviewing parameter settings is crucial when examining the security configuration of an operating system because these settings directly influence the security posture of the system. Parameter settings determine how the operating system behaves and can include settings related to user access controls, password policies, logging levels, and various security features like firewalls or intrusion detection systems.

When these parameters are configured correctly, they help ensure that the system is protected against unauthorized access and other security threats. By assessing these settings, an IS auditor can identify potential vulnerabilities and compliance with security policies.

The other options, while relevant to different aspects of security and operations, do not directly reflect the security configuration controls of the operating system itself. Transaction logs are valuable for auditing and monitoring user activities but do not dictate the security configuration. Authorization tables are important for understanding permissions but are only one aspect of the broader configuration. Routing tables pertain to network configurations and do not influence the security of the operating system's local settings directly. Hence, reviewing parameter settings is essential for a comprehensive security assessment of the operating system.