The BA should approach the solution limitation by assessing the impact on the business operations. This means that the BA should analyze how the inability to meet the SLA in one out of five scenarios would affect the business goals, objectives, performance, value, and risks. The BA should also consider the frequency, severity, and likelihood of the scenarios, and the expectations and needs of the stakeholders. Based on the impact assessment, the BA can then recommend the best course of action, such as modifying the SLA, changing the business process, increasing the scope, or deferring the requirement to a future release. The other options are not the best approaches, as they may either be unrealistic, unnecessary, or ineffective without a proper impact assessment. References:

CBAP / CCBA Certified Business Analysis Study Guide, 2nd Edition, Chapter 7: Solution Evaluation, Section 7.2: Analyze Performance Measures, p. 311-312

A Guide to the Business Analysis Body of Knowledge® (BABOK® Guide), Version 3, Chapter 7: Solution Evaluation, Section 7.2: Analyze Performance Measures, p. 269-270