Quantitative risk assessment is the process of objectively measuring risk by assigning numerical values to the probability of an event occurring and its potential impact. This method is most likely to provide objective support for a security Return on Investment (ROI) case because it allows for the calculation of potential losses in monetary terms, which can be directly compared to the cost of implementing security measures. By quantifying risks and their financial implications, organizations can make informed decisions about where to allocate resources and how to prioritize security investments to maximize ROI. This approach is particularly useful when making a business case to stakeholders who require clear, financial justification for security expenditures.

References: The use of quantitative risk assessment for supporting security ROI is consistent with the principles of Information Security Management, as it provides a structured and measurable method to evaluate and manage risks. It aligns with the Information Risk and Security Lifecycle domains, which emphasize the importance of understanding and addressing risks in a quantifiable manner12345.