When deciding to develop a system with sensitive data, the MOST important thing to include in a business case is a risk assessment to determine the appropriate controls. A business case is a document that provides the rationale and justification for initiating a project or investment1. It includes information such as the objectives, scope, benefits, costs, risks, assumptions, and success criteria of the proposed project or investment2. A risk assessment is a process of identifying, analyzing, and evaluating the potential threats and impacts that could affect the project or investment3. A risk assessment can help to:
* Identify the sources and types of risks associated with developing a system with sensitive data, such as data breaches, data loss, data corruption, unauthorized access, compliance violations, etc.4
* Analyze the likelihood and severity of the risks occurring and their consequences on the project or investment5
* Evaluate the current and planned controls to mitigate or prevent the risks, such as encryption, access control, data backup, data activity monitoring, etc.
* Prioritize the risks and controls based on their importance and urgency
* Communicate and document the risks and controls to stakeholders and decision-makers Therefore, a risk assessment to determine the appropriate controls is essential for developing a business case for a system with sensitive data, as it can help to demonstrate the feasibility, viability, and desirability of the project or investment.
The other options are not as important as option A. While it is useful to have an updated enterprise architecture (EA), a skills gap analysis, and the additional cost of encrypting sensitive data, these are more operational and tactical aspects that can be determined later in the implementation phase. They are not critical for developing a business case for a system with sensitive data, which should focus more on the strategic direction and value proposition of the project or investment. References :=
* How to Write a Business Case - ProjectManager.com2
* Business Case Development - Project Management Institute1
* What is Risk Assessment? Definition & Examples | ASQ3
* Data Security: How to Secure Sensitive Data - DATAVERSITY4
* Risk Analysis: Definition & Examples | ASQ5
* Data access control and data activity monitoring - IBM Cloud ...
* Risk Evaluation: Definition & Examples | ASQ
* Risk Communication: Definition & Examples | ASQ

Risk management strategies are primarily adopted to achieve acceptable residual risk levels, which are the levels of risk that remain after applying risk response measures. Risk management strategies are the approaches or methods that an organization uses to identify, assess, and treat its IT-related risks. Risk management strategies can vary depending on the organization's risk appetite, tolerance, and capacity, as well as the nature and impact of the risks. Some common risk management strategies are: avoid, reduce, transfer, share, or accept. The other options are not as primary, as they are more related to the outcomes or objectives of risk management strategies, rather than the purpose or intention of them. References: : CGEIT Review Manual (Digital Version), Chapter 4: Risk Optimization, Section 4.3: IT Risk Management, Subsection 4.3.1: IT Risk Management Overview, Page 153 : CGEIT Review Manual (Digital Version), Chapter 4: Risk Optimization, Section 4.3: IT Risk Management, Subsection 4.3.2: IT Risk Management Process, Page 156 : CGEIT Review Manual (Digital Version), Chapter 4: Risk Optimization, Section 4.3: IT Risk Management, Subsection 4.3.3:
IT Risk Management Techniques and Tools, Page 158 : Proactive IT Risk Management in an Era of Emerging Technologies1