After stakeholders formally signed off on requirements, the business analyst (BA) received numerous emails requesting...

This answer states that change request log is what the BA should use to help them organize and prioritize requests for changes to Salesforce during UAT after receiving numerous emails from stakeholders who formally signed off on requirements. Change request log is a document or a file that records and tracks requests for changes to a project or a product, such as adding, modifying, or removing a feature or a functionality. Change request log is what the BA should use to help them organize and prioritize requests for changes to Salesforce during UAT because it helps the BA to manage and monitor the requests for changes, and to evaluate and approve or reject them based on their impact, urgency, or feasibility. References: https://trailhead.salesforce.com/en/content/learn/modules/salesforce-business-analyst-quick-look/use-stakeholder-engagement-skills