The saying "Money is a veil (a cover)" by classical economists (based on the neutrality of money) means that Select one: O a. 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. b. money is the principal medium of exchange in most economies. O c. the primary determinant of short-run economic fluctuations is not real variables, but rather changes in the money supply. O d. in the long run money is important to the determination of real variables