【正确答案】 C

【答案解析】Velocity is the average number of times per year each dollar is used to buy goods and services (velocity = GDP/money). Therefore, the money supply multiplied by velocity must equal nominal GDP. The equation of exchange must hold with velocity defined in this way. Letting money supply = M, velocity = V, price = P, and real output = Y, the equation of exchange may be symbolically expressed as : MV = PY.