Which of the following is a primary Keynesian policy lever?

While interest rates and the money supply are important factors in economic management, they fall under the realm of monetary policy rather than fiscal policy. Keynesian theory primarily focuses on government spending and taxation as direct tools to influence aggregate demand, rather than relying on central bank actions related to interest rates and money supply.

This option includes government spending, which is indeed a primary Keynesian policy lever; however, the inclusion of the money supply shifts the focus towards monetary policy. Keynesian economics primarily advocates for the use of fiscal policy tools, specifically government spending and taxes, to manage economic fluctuations and stimulate growth.

Although taxes are a critical component of fiscal policy in Keynesian economics, interest rates are tied to monetary policy. Keynesians argue that adjusting tax rates can effectively influence consumer spending and investment, thereby impacting economic activity. However, the lack of government spending in this option makes it inadequate as a primary lever.