💡 A systems software control refers to security measures that protect software, networks, and IT infrastructure from vulnerabilities and threats. Let’s analyze each option: A. Restricting server room access to specific individuals → This is a physical security control, not a systems software control. B. Housing servers with sensitive software away from environmental hazards → This is an environmental control to protect hardware from risks like floods, fires, or extreme temperatures. C. Ensuring that all user requirements are documented → This relates to project management and system development, not system security. D. Performing intrusion testing on a regular basis → Correct Answer. Intrusion testing (penetration testing) is a security control that identifies vulnerabilities in system software, helping to prevent cyberattacks.