A team using Scrum consistently fails to complete all planned work in a sprint. What should the Scrum Master do first?
Smaller stories enable better estimation and completion within the sprint.
Why this answer
Breaking user stories into smaller pieces enables the team to estimate more accurately and complete work within the sprint. Option A is wrong because simply adding more team members does not address the root cause of incomplete work and can introduce communication overhead. Option C is wrong because the Product Owner is a vital participant in daily stand-ups to provide clarification and prioritize work; removing them hinders collaboration.
Option D is wrong because increasing sprint length reduces feedback frequency and does not solve the underlying issue of work sizing or estimation.