The IS audit manager should specifically review the detailed evidence of the successes and weaknesses of all contingency testing to substantiate the conclusions of the audit of the corporate disaster recovery test. This is because the detailed evidence can provide the audit manager with a clear and objective picture of how well the disaster recovery plan was executed, what issues or gaps were encountered, and what recommendations or actions were taken to address them. The detailed evidence can also help the audit manager to verify the accuracy, completeness, and validity of the audit findings, as well as to evaluate the adequacy and effectiveness of the disaster recovery controls.
The other options are not as specific or relevant as the detailed evidence of all contingency testing. Overviews of interviews between data center personnel and the auditor may provide some useful information, but they are not sufficient to substantiate the conclusions without supporting evidence from the actual testing. Prior audit reports involving other corporate disaster recovery audits may provide some benchmarking or comparison data, but they are not directly related to the current audit scope and objectives. Summary memos reflecting audit opinions regarding noted weaknesses may provide some high-level insights, but they are not enough to substantiate the conclusions without detailed evidence to back them up.
References:
ISACA, CISA Review Manual, 27th Edition, 2019, p. 2411
Disaster Recovery Audit Work Program2

The IS auditor's greatest concern when reviewing a business case for a proposed implementation of a third- party system should be A. Lack of ongoing maintenance costs. This is because ongoing maintenance costs are an essential part of the total cost of ownership (TCO) of a third-party system, and they can have a significant impact on the return on investment (ROI) and the feasibility of the project. If the business case does not include ongoing maintenance costs, it may underestimate the true cost of the project and overestimate the benefits. This could lead to poor decision making and unrealistic expectations.
Lack of training materials (B), lack of plan for pilot implementation , and lack of detailed work breakdown structure (D) are also potential issues that could affect the quality and success of the project, but they are not as critical as lack of ongoing maintenance costs. Training materials can be developed or acquired later, pilot implementation can be planned during the project initiation or planning phase, and work breakdown structure can be refined as the project progresses. However, ongoing maintenance costs are difficult to change or estimate once the project is approved and implemented, and they can have long-term implications for the organization. Therefore, they should be included and analyzed in the business case.

The IS auditor's best course of action when reviewing the use of an outsourcer for disposal of storage media is to determine exposure to the business. Storage media, such as hard disks, tapes, flash drives, or CDs, may contain sensitive or confidential information that needs to be protected from unauthorized access, disclosure, or misuse. The IS auditor should verify that the outsourcer has a process that appropriately sanitizes the media before disposal, such as wiping, degaussing, shredding, or incinerating, and that the process is effective and compliant with the organization's policies and standards. The IS auditor should also assess the potential impact and risk to the business if the storage media is not properly sanitized or disposed of, such as data breaches, reputational damage, legal or regulatory penalties, or loss of competitive advantage. The other options are not the best course of action, because they either do not address the root cause of the problem,or they are reactive rather than proactive measures. References: CISA Review Manual (Digital Version)1, Chapter 5, Section 5.2.7

Developing a risk-based plan considering each entity's business processes would best help to ensure that IS audit still covers key risk areas within the IT environment as part of its annual plan. A risk-based plan is a plan that prioritizes the audit activities based on the level of risk associated with each area or process. A risk- based plan can help to allocate the audit resources more efficiently and effectively, and provide more assurance and value to the stakeholders1.
By considering each entity's business processes, the IS audit can identify and assess the specific risks and controls that affect the IT environment of each entity, and tailor the audit objectives, scope,and procedures accordingly. This can help to address the unique needs and expectations of eachentity, and ensure that the IS audit covers the key risk areas that are relevant and significant to each entity's operations, performance, and compliance2.
The other options are not as effective as developing a risk-based plan considering each entity's business processes in ensuring that IS audit still covers key risk areas within the IT environment as part of its annual plan. Option A, increasing the frequency of risk-based IS audits for each business entity, is not a feasible or efficient solution, as it may increase the audit costs and workload, and create duplication or overlap of audit efforts. Option C, conducting an audit of newly introduced IT policies and procedures, is a limited and narrow approach, as it may not cover all the aspects or dimensions of the IT environment that may have changed or been affected by the split. Option D, revising IS audit plans to focus on IT changes introduced after the split, is a reactive and short-term approach, as it may not reflect the current or future state of the IT environment or the business objectives of each entity.
References:
ISACA, CISA Review Manual, 27th Edition, 2019
ISACA, CISA Review Questions, Answers & Explanations Database - 12 Month Subscription Risk-Based Audit Planning: A Guide for Internal Audit1 Risk-Based Audit Approach: Definition & Example

Social engineering is a technique that exploits human weaknesses, such as trust, curiosity, or greed, to obtain information or access from a target. An employee is induced to reveal confidential IP addresses and passwords by answering questions over the phone is an example of a social engineering attack method, as it involves manipulating the employee into divulging sensitive information that can be used to compromise the network or system. A hacker walks around an office building using scanning tools to search for a wireless network to gain access, an intruder eavesdrops and collects sensitive information flowing through the network and sells it to third parties, and an unauthorized person attempts to gain access to secure premises by following an authorized person through a secure door are not examples of social engineering attack methods, as they do not involve human interaction or deception. References: [ISACA CISA Review Manual 27th Edition], page 361.