Final answer:
Scope Planning is the project management activity where Work Breakdown Structures (WBS) from past projects are reviewed and tailored for a new project to define its total scope in a structured way.
Step-by-step explanation:
The project management activity that involves reviewing Work Breakdown Structures (WBS) of similar projects and tailoring them to your current project is C) Scope Planning. During this process, project managers define the total scope of the project by developing a WBS, which is a hierarchical decomposition of the total scope of work to be carried out by the project team. By analyzing WBSs from past projects, project managers can identify useful patterns and structures that can be adapted to the new project, thus ensuring a thorough plan for project completion.