According to the PMBOK Guide, scope management in agile projects is different from scope management in predictive life cycle projects. In agile projects, the scope is not fixed or detailed at the beginning of the project, but rather it is progressively elaborated and refined throughout the project. Agile projects use an adaptive and iterative approach to deliver value to the customer in short and frequent increments, called sprints or iterations. Agile projects use techniques such as user stories, product backlog, story mapping, story points, and minimum viable product (MVP) to define, prioritize, estimate, and validate the scope. Therefore, the project manager should spend a short amount of time defining the scope and building prototypes to refine the requirements, rather than creating a detailed scope baseline or a rigid plan. By doing so, the project manager can:

Involve the customer and the team in defining and clarifying the scope

Incorporate feedback and changes quickly and easily

Deliver the most valuable features and functionalities first

Reduce waste and rework

Increase customer satisfaction and trust

The other options are not the best choices, because:

Creating a scope baseline and putting the rest as backlog activities would limit the flexibility and responsiveness of the project, and would not allow the scope to evolve based on customer needs and feedback.

Estimating the work the team can complete and defining story sizes to keep the project under control would be part of the scope management process, but not the only or the best way to manage and control the scope. The project manager should also prioritize, validate, and adjust the scope as the project progresses.

Developing a plan to complete more work in less time would not be realistic or sustainable, and would compromise the quality and value of the project. The project manager should focus on delivering the right work, not more work. References:

Scope Management | PMI

Agile Scope Management: Refactor Your PMP - LeadingAgile

Considerations for Agile/Adaptive Projects | PMP - GreyCampus