Which Constitutional Article discusses states' powers?

The correct answer is that Article IV of the Constitution discusses states' powers. This article addresses the relationship between states, as well as the relationship between states and the federal government. It includes important clauses such as the Full Faith and Credit Clause, which requires states to respect the public acts, records, and judicial proceedings of every other state. Additionally, Article IV outlines the rights of states to create and enforce their own laws and provides for the admission of new states into the Union.

Article I primarily deals with the legislative branch and the powers granted to Congress, while Article II focuses on the executive branch and the powers of the President. Article VI contains the Supremacy Clause, which establishes that federal law takes precedence over state law. Each of these articles serves a different purpose, but Article IV specifically addresses the powers and responsibilities of states, making it the best choice among the options provided.