Which is the most accurate statement?

A) The quantity theory of money and the equation of exchange are two ways of saying exactly the same thing.
B) The crude quantity theory of money very accurately describes the relation between the money supply and the price level.
C) According to the crude quantity theory,Q and V are constants.
D) One of our main economic problems has been that the equation of exchange has not been balanceD.

According to the crude quantity theory, the money supply (M) is directly proportional to the price level (P) and inversely proportional to the velocity of money (V). In this theory, Q (the level of output) and V are assumed to be constants. Therefore, option C is the most accurate statement. Option A is incorrect because although the quantity theory of money and the equation of exchange are related concepts, they are not the same thing. Option B is incorrect because the crude quantity theory of money has limitations, and it cannot accurately describe the intricate relationship between money supply and price level. Option D is incorrect because the equation of exchange is just a tool to explain the relationship between money supply and price level, and it cannot create economic problems.