Each of the Following Is Something That Economists Don't Know

Multiple Choice

Each of the following is something that economists don't know about the microfoundations of macroeconomics except

A) how aggregate consumption and savings decisions are made.
B) what determines the large shifts in the natural rate of unemployment.
C) what can be done to lower the natural rate of unemployment.
D) when it is beneficial for businesses to undertake projects that involve investment spending.