The best thing to include in a business case when the return on investment (ROI) for an information security initiative is difficult to calculate is an estimated reduction in risk. Risk reduction is the expected benefit of implementing an information security initiative, as it reduces the likelihood and impact of threats and vulnerabilities that may affect the organization’s information assets and systems. By estimating the reduction in risk, the information security manager can demonstrate the value and benefits of the information security initiative to the organization’s performance, reputation, and competitiveness. The information security manager can also compare the estimated reduction in risk with the estimated cost of the information security initiative to determine its cost-effectiveness and feasibility. The other options are not the best thing to include in a business case, although they may be some inputs or outputs of the risk assessment process. A projected increase in maturity level is a potential outcome of implementing an information security initiative, as it improves the organization’s capabilities and processes for managing information security risks. However, it does not necessarily reflect the actual reduction in risk or the ROI of the information security initiative. A projected cost over time is a component of calculating the ROI of an information security initiative, as it reflects the total cost of ownership and maintenance of the initiative. However, it does not indicate the expected benefit or value of the initiative. An estimated increase in efficiency is a possible benefit of implementing an information security initiative, as it may enhance the organization’s productivity and performance. However, it may not be directly related to the reduction in risk or the ROI of the information security initiative.