Which One of the Following Statements Is True

Which one of the following statements is true?

A) Over the years, real consumption spending has been more volatile than real investment spending.
B) Over the years, real investment spending has been more volatile than real consumption spending.
C) Domestic real investment in the United States was highest during the Great Depression.
D) In the Keynesian model, changes in the volume of real investment spending are fully explained by changes in the real interest rate.