The correct answer is D - Work with the team to ensure that acceptance criteria is being properly defined and understood.
Incomplete work that fails to meet stakeholder expectations often results from unclear or misunderstood acceptance criteria. Clarifying the definition of "done" and ensuring alignment between the Product Owner and development team can drastically reduce rework and defects.
From the PMI Agile Practice Guide:
"Clear and testable acceptance criteria help ensure shared understanding. Quality issues frequently stem from misaligned expectations or vague requirements." (PMI Agile Practice Guide, Section 5.2 - Definition of Done and Acceptance Criteria) Mike Griffiths writes:
"Teams must understand what success looks like for each story. Poorly defined or misunderstood acceptance criteria are a major cause of defects and missed expectations." (Mike Griffiths, PMI-ACP Exam Prep Book, Chapter 6 - Problem Detection and Resolution) Other options explained:
* A (spike) is used for research or uncertainty-not fixing misunderstood requirements.
* B (burndown chart) helps track progress, not resolve defects.
* C may help indirectly but doesn't address the core problem of unclear requirements.