The primary focus of a lessons learned exercise following a successful response to a cybersecurity incident is to evaluate how the incident management processes were executed, and to identify the strengths, weaknesses, best practices, and improvement opportunities for future incidents. A lessons learned exercise is not meant to determine the root cause, the attack vectors, or the recovery time of the incident, but rather to assess the performance and effectiveness of the incident response team and the incident response plan.
References: The CISM Review Manual 2023 states that "post-incident reviews are an essential part of the incident response process" and that "they provide an opportunity to assess the performance of the incident response team, identify areas for improvement, and document lessons learned and best practices" (p. 191).
The CISM Review Questions, Answers & Explanations Manual 2023 also provides the following rationale for this answer: "How incident management processes were executed is the correct answer because it is the primary focus of a lessons learned exercise, which aims to evaluate the incident response capability and to implement corrective actions and improvement plans" (p. 97). Additionally, the Cybersecurity Incident Response Exercise Guidance article from the ISACA Journal 2022 states that "The AAR [after-action review] should include the date and time of the exercise, a list of participants, scenario descriptions, findings (generic and specific), observations with recommendations, lessons learned and an evaluation of the exercise (strengths, weaknesses, lessons learned)" (p. 3)1

When a new information security manager is developing an information security strategy for a non-regulated organization, reviewing the management's business goals and objectives would be the most helpful. This is because the information security strategy should be aligned with and support the organization's vision, mission, values, and strategic direction. The information security strategy should also enable the organization to achieve its desired outcomes, such as increasing revenue, reducing costs, enhancing customer satisfaction, or improving operational efficiency. By reviewing the management's business goals and objectives, the information security manager can understand the business context, needs, and expectations of the organization, and design the information security strategy accordingly. The information security manager can also communicate the value proposition and benefits of the information security strategy to the management and other stakeholders, and gain their support and commitment.
References = CISM Review Manual, 16th Edition, Chapter 1: Information Security Governance, Section:
Information Security Strategy, page 211; CISM Review Questions, Answers & Explanations Manual, 10th Edition, Question 48, page 452.

Business impact analysis (BIA) is the most helpful in determining the criticality of an organization's business functions because it is a process of identifying and evaluating the potential effects of disruptions or interruptions to those functions. BIA helps to prioritize the recovery of the most critical functions and to estimate the resources and time needed for the recovery. Therefore, business impact analysis (BIA) is the correct answer.
References:
https://www.linkedin.com/pulse/business-continuity-critical-functions-tino-marquez
https://www.techtarget.com/searchitchannel/feature/Business-impact-analysis-for-business-continuity- Understanding-impact-criticality