Local systems can eliminate vulnerabilities by: A. Patch systems and software effectively and continuously. Regularly applying security patches and updates to both the operating system and software applications is a critical practice to eliminate vulnerabilities. These patches often address known security flaws and help protect the system from exploitation by malicious actors. Effective and continuous patch management is a fundamental component of a robust cybersecurity strategy to keep local systems secure. Options B and C are not standard practices for eliminating vulnerabilities. Option D, testing and deploying patches on a focused set of systems, is related to patch management but doesn't address the "effective and continuous" aspect of vulnerability elimination.

Answer should be A, D makes no sense A. Patch systems and software effectively and continuously.