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

The auditor's primary concern when capacity management for a key system is being performed by IT with no input from the business would be an unanticipated increase in business's capacity needs. This could result in performance degradation, service disruption or customer dissatisfaction if IT is not able to provide sufficient capacity to meet the business demand. Failure to maximize the use of equipment, cost of excessive data center storage capacity or impact to future business project funding are secondary concerns that relate to resource optimization or budget allocation, but not to service delivery or customer satisfaction. References: ISACA, CISA Review Manual, 27th Edition, 2018, page 374

The IS auditor's most important course of action after finding that several similar incidents were logged during the audit period is to determine if a root cause analysis was conducted. A root cause analysis is a systematic process that identifies the underlying causes of system failures or incidents. A root cause analysis can help to prevent recurrence of similar incidents, improve system performance and reliability, and enhance incident management processes. The IS auditor should evaluate whether a root cause analysis was performed for each incident, whether it was timely and thorough, and whether it resulted in effective corrective actions.

The most beneficial stage of the system development life cycle (SDLC) to consider data privacy principles is D: Requirements definition. This is because data privacy principles should be integrated into the design and development of customer-facing IT applications from the very beginning, not as an afterthought or a retrofit1. By considering data privacy principles in the requirements definition stage, the developers can identify the personal data that will be collected, processed, stored, and shared by the application, and ensure that they comply with the relevant laws and regulations, such as the General Data Protection Regulation (GDPR)2. They can also apply the principles of data minimization, purpose limitation, transparency, consent, and security to protect the privacy rights and interests of the customers3.