According to the PMBOKĀ® Guide, the Scope Baseline is the approved version of a scope statement, Work Breakdown Structure (WBS), and its associated WBS dictionary. It is a component of the Project Management Plan and can be changed only through formal change control procedures.
Project Scope Statement: Includes the description of the project scope, major deliverables, assumptions, and constraints.
WBS: A hierarchical decomposition of the total scope of work to be carried out by the project team to accomplish the project objectives and create the required deliverables.
WBS Dictionary: A document that provides detailed deliverable, activity, and scheduling information about each component in the WBS (such as code of account identifier, description of work, responsible organization, and quality requirements).
Choice A (Scope plan) is not a formal PMI term; it likely refers to the Scope Management Plan.
Choice B (Product scope) refers only to the features and functions that characterize a product, service, or result.
Choice C (Scope management plan) is a component of the project management plan that describes how the scope will be defined, developed, monitored, controlled, and validated. It describes the process, whereas the baseline is the actual approved scope.