The correct answer is D - Implement a spike to enhance creativity by experimenting with new techniques and process ideas in order to discover more efficient and effective ways of working. A spike is a time-boxed research or prototyping activity used to explore uncertainty, investigate a technology, or gain deeper knowledge of an implementation. Spikes are especially useful when a team lacks familiarity with certain technologies, as they reduce risk and support better estimation. From the PMI Agile Practice Guide: "Spikes are a type of exploration that agile teams use when they are uncertain about a technology or technique. They are time-boxed research efforts aimed at reducing risk and improving future delivery." (PMI Agile Practice Guide, Section 5.3 - Spikes) Mike Griffiths further explains: "Spikes allow the team to gain knowledge needed to understand a technical or design problem. They are particularly useful when the team lacks domain or technical experience and are often used to improve estimation accuracy." (Mike Griffiths, PMI-ACP Exam Prep Book, Chapter 5 - Adaptive Planning) Why other options fall short: * A and B manipulate iteration length without addressing the core problem (lack of technical knowledge). * C increases overhead without solving the learning gap or preventing the root cause (rework). answers and comprehensive explanations drawn from authoritative sources including the PMI Agile Practice Guide, PMBOK Guide, Mike Griffiths' PMI-ACP Exam Prep Book, and Andy Crowe's PMI-ACP Exam materials. ##################################################