The correct answer is A - Create a user story for this new improvement and put it in the product backlog for prioritization and validation by the customer. Agile is iterative and feedback-driven. New requirements or enhancements identified during reviews are treated like any other backlog item: they are created as user stories, evaluated, and prioritized collaboratively.
From the PMI Agile Practice Guide:
"Feedback during review meetings may lead to new stories. These are added to the product backlog and prioritized based on value, risk, and customer need." (PMI Agile Practice Guide, Section 5.2 - Product Review and Feedback) Mike Griffiths explains:
"Agile welcomes change-even late in development. New feedback should be captured as stories, then reviewed and prioritized by the Product Owner in alignment with business goals." (Mike Griffiths, PMI-ACP Exam Prep, Chapter 3 - Value-Driven Delivery) Incorrect options:
* B assumes premature prioritization.
* C implies scope creep, which contradicts agile's flexibility.
* D contradicts team empowerment and planning integrity.