The most accurate statement regarding the long-term implications of the government implementing expansionary fiscal policies indefinitely is:
Decreases in federal government revenue and increasing expenses cause large deficits and add to the national debt, straining the economy.
This response captures the essence of potential long-term effects of sustained expansionary fiscal policies, such as increased government spending without corresponding increases in revenue, leading to rising deficits and debt. Over time, this can put significant strain on the economy, potentially crowding out private investment, increasing borrowing costs, and creating challenges for future fiscal policy decisions.