The Real Money Supply

The real money supply

A) tends to grow over time because growing economies need increasingly large quantities of money to support their activity.
B) grows only in response to deliberate contractions in the money supply that lower the price level at a more rapid pace.
C) moves up or down only when the price level changes.
D) is impossible to measure because of the confusion caused by international transactions in the currencies of other countries.
E) is the primary policy tool of the Keynesian economist.