In Six Sigma methodology, different belt levels signify varying degrees of expertise and responsibility within process improvement projects. Understanding these roles is crucial for effective implementation across an organization.

White Belt: Individuals at this level have a basic understanding of Six Sigma concepts and may participate in local problem-solving teams but do not lead projects or mentor others.

Yellow Belt: Yellow Belts possess a foundational knowledge of Six Sigma and assist with project tasks and data collection. They do not typically allocate resources for projects.

Green Belt: Green Belts work on Six Sigma projects part-time, often under the guidance of Black Belts. They analyze and solve quality problems within their specific areas but do not provide executive coaching.

Black Belt: Black Belts are full-time professionals who lead problem-solving projects and report to project sponsors or Champions. They are responsible for project execution and achieving measurable results.

Therefore, among the options provided, the statement "Black belts report to project sponsors" (Option A) best differentiates the role of the various belts.