The correct answer is D - Engaged key stakeholders periodically to collect requirements.
Agile is based on frequent stakeholder collaboration. Continuous engagement ensures evolving needs are captured and prevents misalignment. Waiting for planning meetings or demos is too late to catch missing input.
PMI Agile Practice Guide:
"Agile teams ensure stakeholder engagement is ongoing throughout the project. This helps validate requirements and prevent surprises during reviews." (PMI Agile Practice Guide, Section 4.2 - Stakeholder Engagement) Mike Griffiths:
"Stakeholders should be consulted early and often. Relying on static requirements leads to gaps. Agile teams maintain constant feedback loops." (PMI-ACP Exam Prep, Chapter 3 - Value-Driven Delivery) Incorrect options:
* A is too early and one-time.
* B may help but is reactive.
* C is a predictive approach inconsistent with agile.