Social engineering exploits human vulnerabilities, and the most effective mitigation is training employees to recognize and respond to these threats. Security awareness programs help build a culture of vigilance, equipping employees with the knowledge to identify phishing attempts, suspicious behavior, and other social engineering tactics.
* Multi-factor Authentication (MFA) (Option A): Enhances access control but does not address the human vulnerability to social engineering.
* Access History Log Review (Option C): Useful for post-incident analysis but does not prevent incidents.
* File Encryption with Password Protection (Option D): Adds security layers but is ineffective if the password is compromised.
Reference: ISACA CISA Review Manual, Job Practice Area 4: Protection of Information Assets.

According to the ISACA's Information Security Governance Guidance for Boards of Directors and Executive Management, the highest level of maturity of an information security program is Level 5: Optimized, which means that the program is aligned with the business objectives and strategy, and continuously monitors and improves its performance and effectiveness. A framework is in place to measure risks and track effectiveness, and the program is proactive, adaptive, and innovative.
The other options represent lower levels of maturity:
* A training program is in place to promote information security awareness. This is Level 2: Repeatable, which means that the program has some basic policies and procedures, and provides awareness training to employees.
* Information security policies and procedures are established. This is Level 3: Defined, which means that the program has formalized policies and procedures, and assigns roles and responsibilities for information security.
* The program meets regulatory and compliance requirements. This is Level 4: Managed, which means that the program has established metrics and reporting mechanisms, and complies with relevant laws and regulations.
References: : ISACA. (2001). Information Security Governance Guidance for B

Antivirus software has been implemented on the guest operating system only is the observation that an IS auditor would consider the greatest risk when conducting an audit of a virtual server farm for potential software vulnerabilities. A virtual server farm is a collection of servers that run multiple virtual machines (VMs) on a single physical host using a software layer called a hypervisor. A guest operating system is the operating system installed on each VM. Antivirus software is a software program that detects and removes malicious software from a computer system. If antivirus software has been implemented on the guest operating system only, it means that the hypervisor and the host operating system are not protected from malware attacks, which could compromise the security and availability of all VMs running on the same host.
Therefore, antivirus software should be implemented on both the guest and host operating systems as well as on the hypervisor. References: CISA Review Manual, 27th Edition, page 378