Which decision limited the reach of the Commerce Clause by addressing gun regulation in a school zone?

• A. United States v. Lopez
• B. McCulloch v. Maryland
• C. Alden v. Maine
• D. Printz v. United States

Answer: (A)

The question tests how far Congress can reach under the Commerce Clause when regulating guns in a school zone. United States v. Lopez is the decision that set a limit by striking down the Gun-Free School Zones Act because simply possessing a gun in a school zone was not an economic activity that substantially affects interstate commerce. This ruling shows that the Commerce Clause has bounds and that not every issue related to guns or crime automatically falls under federal regulatory power; some matters are more appropriately left to the states.

Other listed cases address different aspects of federal power. McCulloch v. Maryland deals with federal supremacy and implied powers, not a limit on the Commerce Clause in the school-zone gun context. Alden v. Maine concerns state sovereign immunity, and Printz v. United States concerns requiring state officers to enforce federal laws under the Tenth Amendment.