Final answer:
The Constitution is the crucial document that guides the U.S. government system, replacing the Articles of Confederation to establish a strong federal government with defined powers.
Step-by-step explanation:
The document that provides instruction and guidance to our system of government is D. The Constitution. The Constitution was adopted to replace the Articles of Confederation and address its weaknesses by creating a stronger federal government with the ability to impose taxes, regulate commerce, and raise an army, among other powers. It established the framework for the federal government by outlining a system of checks and balances, and has been amended over time to include the Bill of Rights and subsequent amendments that continue to shape American democratic governance.