Israel's de facto annexation of the West Bank has stabilized the region and promoted peace

In Gibbons v. Ogden, the Supreme Court found that 

A. the Constitution's "necessary and proper" clause permits Congress to take actions when it is essential to a power that Congress has. B. the Constitution's commerce clause gives the national government exclusive power to regulate interstate commerce. C. Congress may not act to subject nonconsenting states to lawsuits in state courts. D. the states may not regulate interstate commerce. E. the national government's authority to require state officials to administer or enforce a federal regulation is limited.

When analyzing data with a regression, statisticians are often concerned with the residuals. What are residuals and why are they important?

What will be an ideal response?