Which of the following best describes the purpose of a requirements traceability matrix? It's used to make sure that all subplans of the Project Management plan have been created. It helps you understand the source of each requirement, and how that requirement was verified in a later deliverable. It describes how work packages are decomposed from deliverables. It's used to trace the source of every change, so that you can keep track of them as you control scope and verify that the change was properly implemented