According to the PMBOK® Guide (Project Management Body of Knowledge), specifically within the Project Risk Management knowledge area and the Perform Qualitative Risk Analysis process, risks are assessed based on their probability of occurrence and their impact on project objectives.

Risk 2 (Option B): This risk has a High (H) probability of occurrence. Probability refers specifically to the likelihood that the risk will happen. Since Risk 2 is the only risk in the provided table with a " High " probability, it is the one most likely to occur compared to the others (which are Low or Medium).

Risk 1: Has a Low (L) probability.

Risk 3: Has a Low (L) probability.

Risk 4: Has a Medium (M) probability.

While the " Impact " column is used to determine the overall Risk Rating or priority (where Risk 2 would also be the highest priority because it is High/High), the specific question asks which is " most likely to occur, " which is a direct reference to the Probability metric alone.

In the PMI framework, the Perform Qualitative Risk Analysis process uses these qualitative descriptors (Low, Medium, High) to help the project manager and team prioritize which risks require the most immediate attention in the Plan Risk Responses process.