According to the PMBOK® Guide, Project Scope Management includes the processes required to ensure that the project includes all the work required, and only the work required, to complete the project successfully. To manage scope correctly, a project manager must follow the specific sequence of processes defined within the Scope Management Knowledge Area.

The six core processes are:

Plan Scope Management: Creating a scope management plan that documents how the project and product scope will be defined, validated, and controlled.

Collect Requirements: Determining, documenting, and managing stakeholder needs and requirements to meet project objectives.

Define Scope: Developing a detailed description of the project and product.

Create WBS: Subdividing project deliverables and project work into smaller, more manageable components.

Validate Scope: Formalizing acceptance of the completed project deliverables.

Control Scope: Monitoring the status of the project and product scope and managing changes to the scope baseline.

Analysis of Other Options:

A. Control Schedule; Control Costs: These belong to the Schedule Management and Cost Management Knowledge Areas, respectively. While related to overall project health, they are not tasks used to manage scope specifically.

B. Develop Schedule: This is a Schedule Management process. Managing scope is the precursor to developing a schedule, but the schedule itself is not a scope management task.

D. Control Costs; Manage Stakeholder Engagement: These are processes from other Knowledge Areas. " Keeping budget under control " is a goal of Cost Management, not a defined process for managing Scope.