Which statement best explains the importance of documenting requirements systematically?

Documenting requirements systematically is essential because it establishes a clear, shared understanding of what is needed from the stakeholders. This documentation serves as a reference that enhances negotiation by providing a concrete basis for discussions among stakeholders with varying interests and priorities. When requirements are well-documented, stakeholders can more easily identify their needs and expectations, leading to more productive discussions and agreements.

While other options highlight relevant aspects of project management, they do not capture the crux of how systematic documentation contributes to negotiation specifically. For instance, although facilitating implementation and supporting communication are important, they don't directly address the aspect of aligning differing viewpoints and reaching consensus among stakeholders as effectively as the correct answer does. In short, systematic documentation is instrumental in managing stakeholder expectations and fostering agreement on project requirements, which is vital for successful project outcomes.