Which of the following departments manages the nation's finances?

The Department of Treasury is responsible for managing the nation's finances. This crucial role includes overseeing the production of currency, managing federal accounts, collecting taxes, and formulating economic policy. The Treasury also plays a significant part in managing the government's debt and producing financial reports that are essential for decision-making at various levels of government. Its responsibilities are fundamental in ensuring the economic stability and financial health of the country.

The other departments listed focus on areas outside financial management. The Department of Commerce deals with trade and economic growth; the Department of Labor focuses on labor standards and workforce issues; while the Department of Defense is responsible for military and national security matters. Each of these departments has distinct functions, which further underscores the Treasury's unique role in handling the nation's finances.