A state-of-the-art product was delivered at project close, but the customer claims it was not built to the required specifications. What should the project manager have done to prevent this?

The correct answer is to capture the customer's requirements to ensure the product meets the customer's standards. This is fundamental to project success. A project is deemed successful when it meets or exceeds stakeholder expectations, and those expectations are primarily defined by the requirements. Thoroughly capturing, documenting, and validating requirements ensures that the delivered product aligns with what the customer actually needs and expects. Modifying customer requirements to match supplier standards is incorrect because it prioritizes the supplier over the customer, leading to dissatisfaction. Scheduling an iteration review planning meeting appropriately, while good practice in agile, doesn't directly address the core issue of understanding and meeting customer requirements if those requirements weren't properly captured initially. Including stakeholders in a sprint retrospective is valuable for process improvement but occurs after work has been done; it wouldn't prevent the initial mismatch in requirements.