Just before a scheduled product launch, the customer declined to accept the final deliverable after...

To prevent the issue of the customer declining to accept the final deliverable after the demo, the project manager should prioritize frequent releases and feedback loops. By releasing new features or updates frequently, customers have the opportunity to provide feedback earlier in the process, which allows for adjustments to be made during development rather than at the end. This iterative process ensures that the final product better aligns with the customer's expectations and requirements.