The saying "money is a veil." means that a. the primary determinant of short-run economic fluctuations is not real variables, but rather changes in the money supply. b. in the long run money is of no importance to the determination of either real or nominal variables. c. money is the principal medium of exchange in most economies. d. while nominal variables are the first thing we may observe about an economy, what's important are the real variables and the forces that determine them