The risk register is a document that records the identified risks, their analysis, and their responses. It is a useful tool for monitoring and controlling the risks throughout the project lifecycle. However, the risk register is not a static document and it should be updated regularly to reflect the changes in the risk environment and the project status. Therefore, when reviewing the risk register, a risk practitioner should not only look at the risk ratings, but also the assumptions and the rationale behind them. Different business units may have different perspectives, contexts, and data sources for the same risk scenario, which can result in significant variances in inherent risk. Inherent risk is the risk level before considering the existing controls or responses.
Therefore, the best course of action is to review the assumptions of both risk scenarios to determine whether the variance is reasonable or not. This can help to identify any errors, inconsistencies, or biases in the risk assessment process, and to ensure that the risk register reflects the current and accurate state of the risks. References = Risk and Information Systems Control Study Manual, Chapter 3, Section 3.2.1, p. 106-107

Risk response strategy is the approach that an organization takes to address the risks that it faces across its various functions, processes, and activities. Risk response strategy involves selecting and implementingthe appropriate risk response options, such as avoidance, mitigation, transfer, or acceptance, for each risk, based on the risk level, the risk appetite, and the cost-benefit analysis1.
The most important consideration for senior management when developing a risk response strategy is the risk appetite of the organization. Risk appetite is the amount and type of risk that an organization is willing to accept in order to achieve its objectives. Risk appetite reflects the organization's risk attitude and its willingness to take on risk in specific scenarios. Risk appetite is usually expressed in a qualitative statement approved by the board of directors2.
Considering the risk appetite of the organization is essential for developing a risk response strategy, because it can help to:
Align the risk response strategy with the overall business strategy and vision, and ensure that the risk response options support the achievement of the organizational objectives Balance the risk response strategy with the expected benefits and opportunities, and ensure that the risk response options do not eliminate or reduce the potential value or performance of the organization Enhance the risk response strategy with the stakeholder expectations and requirements, and ensure that the risk response options meet the needs and interests of the customers, suppliers, partners, regulators, and other parties Optimize the risk response strategy with the available resources and capabilities, and ensure that the risk response options are feasible and cost-effective for the organization34 The other options are not as important as the risk appetite of the organization for developing a risk response strategy, but rather some of the factors or outcomes of it. Cost of controls is the amount of resources and funds that are required to implement and maintain the risk response controls, such as policies, procedures, or technologies, that aim to prevent or reduce the negative effects of the risks. Cost of controls is a factor that can affect the selection and implementation of the risk response options, but it is not the primary consideration for developing the risk response strategy. Risk tolerance is the acceptable variation in the outcomes related to specific objectives or risks. Risk tolerance is a factor that can measure the risk analysis and guide the risk response, but it is not the primary consideration for developing the risk response strategy. Probability definition is the process of estimating the likelihood or frequency of the risk events, based on historical data, statistical analysis, expert judgment, or other methods. Probability definition is an outcome of the risk analysis that can inform the risk response, but it is not the primary consideration for developing the risk response strategy. References = Risk Response - ISACA Risk Appetite vs. Risk Tolerance: What is the Difference? - ISACA Risk Response Strategies: Types & Examples (+ Free Template) Risk Response Strategy - ISACA
[CRISC Review Manual, 7th Edition]

The most important step when developing risk scenarios using a list of generic scenarios based on industry best practices is to validate the generic risk scenarios for relevance. The generic risk scenarios may not be applicable or suitable for the specific context, objectives, and environment of the organization. Therefore, the risk practitioner should validate the relevance of the generic risk scenarios by comparing them with the organization's risk profile, risk appetite, and risk criteria. Assessing generic risk scenarios with business users, selecting the maximum possible risk scenarios from the list, and identifying common threats causing generic risk scenarios are other steps that may be useful, but they are not as important as validating the relevance of the generic risk scenarios. References = ISACA Certified in Risk and Information Systems Control (CRISC) Certification Exam Question and Answers, question 12; CRISC Review Manual, 6th Edition, page 215.

According to the CRISC Review Manual (Digital Version), risk management strategies are primarily adopted to achieve acceptable residual risk levels, which are the remaining risk levels after implementing risk response actions. Residual risk levels should be aligned with the organization's risk appetite and risk tolerance, which are the amount and type of risk that the organization is willing to accept in pursuit of its objectives and the acceptable variation in outcomes related to specific performance measures linked to objectives. Risk management strategies are the approaches or methods used to address risks, such as avoidance, mitigation, transfer, sharing, or acceptance. Risk management strategies should be based on a cost-benefit analysis of the alternatives available and the value of the assets at risk.
References = CRISC Review Manual (Digital Version), Chapter 3: IT Risk Response, Section 3.3: Risk Response Options, pp. 166-1691

According to the CRISC Review Manual1, senior management support is the commitment and involvement of the top-level executives and leaders in the risk management process. Senior management support is the most important enabler of effective risk management, as it helps to establish and communicate the risk vision, strategy, and culture of the organization. Senior management support also helps to allocate the necessary resources, authority, and accountability for risk management, and to ensure the alignment of the risk management objectives and activities with the organization's strategy, goals, and values. References = CRISC Review Manual1, page 198.