Given the constraints of unclear requirements, a fixed deadline, and a fixed budget, and the fact that the client is unable to provide a product owner and wants to be involved only a few times during the project, the project manager should agree up front on a minimum viable product (MVP), establish deadlines for review, and run the project with a backlog and weekly sprints. This approach allows for flexibility in dealing with unclear requirements, provides regular checkpoints for client involvement, and ensures that the project delivers value incrementally, which is particularly important in a large-scale project with a fixed deadline and budget. References: Project Management Institute. (2021). A Guide to the Project Management Body of Knowledge (PMBOKGuide)-Seventh Edition. Project Management Institute, Inc.