Threat intelligence is the most helpful method for protecting an enterprise from advanced persistent threats (APTs), as it provides relevant and actionable information about the sources, methods, and intentions of the adversaries who conduct APTs. Threat intelligence can help to identify and anticipate the APTs that target the enterprise, as well as to enhance the detection, prevention, and response capabilities of the information security program. Threat intelligence can also help to reduce the impact and duration of the APTs, as well as to improve the resilience and recovery of the enterprise. Threat intelligence can be obtained from various sources, such as internal data, external feeds, industry peers, government agencies, or security vendors.
The other options are not as helpful as threat intelligence, as they do not provide a specific and timely way to protect the enterprise from APTs. Updated security policies are important to establish the rules, roles, and responsibilities for information security within the enterprise, as well as to align the information security program with the business objectives, standards, and regulations. However, updated security policies alone are not enough to protect the enterprise from APTs, as they do not address the dynamic and sophisticated nature of the APTs, nor do they provide the technical or operational measures to counter the APTs. Defined security standards are important to specify the minimum requirements and best practices for information security within the enterprise, as well as to ensure the consistency, quality, and compliance of the information security program. However, defined security standards alone are not enough to protect the enterprise from APTs, as they do not account for the customized and targeted nature of the APTs, nor do they provide the situational or contextual awareness to deal with the APTs. Regular antivirus updates are important to keep the antivirus software up to date with the latest signatures and definitions of the known malware, viruses, and other malicious code. However, regular antivirus updates alone are not enough to protect the enterprise from APTs, as they do not detect or prevent the unknown or zero-day malware, viruses, or other malicious code that are often used by the APTs, nor do they provide the behavioral or heuristic analysis to identify the APTs. References = CISM Review Manual, 16th Edition, ISACA, 2022, pp. 211-212, 215-216, 233-234, 237-238.
CISM Questions, Answers & Explanations Database, ISACA, 2022, QID 1021.
Advanced Persistent Threats and Nation-State Actors 1
Book Review: Advanced Persistent Threats 2
Advanced Persistent Threat (APT) Protection 3
Establishing Advanced Persistent Security to Combat Long-Term Threats 4 What is the difference between Anti - APT (Advanced Persistent Threat) and ATP (Advanced Threat Protection)5

Criteria for activation are essential to ensure that the BCP is triggered appropriately in response to a disruption.
"The BCP should include clearly defined activation criteria to ensure that plans are invoked when necessary."
- CISM Review Manual 15th Edition, Chapter 3: Information Security Program Development and Management, Section: Business Continuity Planning* ISACA's practice questions confirm that criteria for activation are core to a BCP's effectiveness.

The first step when developing a business case for a new intrusion detection system (IDS) solution is to define the issues to be addressed. A business case is a document that provides the rationale and justification for initiating a project or investment. It typically includes information such as the problem statement, the objectives, the alternatives, the costs and benefits, the risks and assumptions, and the expected outcomes. The first step in developing a business case is to define the issues to be addressed, which means identifying and describing the current situation, the problems or challenges faced by the organization, and the needs or opportunities for improvement. By defining the issues to be addressed, the information security manager can establish the scope and purpose of the business case, and provide a clear and compelling problem statement that explains why a new IDS solution is needed. The other options are not the first step when developing a business case for a new IDS solution, although they may be part of the subsequent steps. Performing a cost-benefit analysis is a step that involves comparing the costs and benefits of different alternatives, including the new IDS solution and the status quo. A cost-benefit analysis can help evaluate and justify the feasibility and desirability of each alternative, and support the decision-making process. Calculating the total cost of ownership (TCO) is a step that involves estimating the direct and indirect costs associated with acquiring, operating, maintaining, and disposing of an asset or a system over its entire life cycle. A TCO calculation can help determine the long-term financial implications of investing in a new IDS solution, and compare it with other alternatives. Conducting a feasibility study is a step that involves assessing the technical, operational, legal, and economic aspects of implementing a project or an investment. A feasibility study can help identify and mitigate any potential issues or risks that may affect the success of the project or investment, and provide recommendations for improvement

Compliance status reporting is the best element of a service contract that would enable an organization to monitor the information security risk associated with a cloud service provider, as it provides the organization with regular and timely information on the cloud service provider's compliance with the agreed-upon security requirements, standards, and regulations. Compliance status reporting also helps the organization to identify any gaps or issues that need to be addressed or resolved, and to verify the effectiveness of the cloud service provider's controls. (From CISM Review Manual 15th Edition) References: CISM Review Manual 15th Edition, page 184, section 4.3.3.2.