Long user stories can hinder sprint completion and value delivery. The Scrum Master should facilitate a team review of the user stories and work with the product owner to ensure the stories are right-sized and follow the INVEST principle (Independent, Negotiable, Valuable, Estimable, Small, Testable).
Option A aligns with Scrum and Agile practices of team-based refinement and collaboration with the product owner.
Option B unnecessarily involves external stakeholders.
Option C puts the burden on one team member.
Option D promotes discussion but lacks action.
References:
Agile Practice Guide, Chapter 5 - Product Backlog Refinement
Scrum Guide - Sprint Planning and Story Sizing
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