单选题 According to the quantity theory of money, if nominal GDP is $3 trillion and the money supply is $0.5 trillion, the velocity of the money supply is closest to:
【正确答案】 B
【答案解析】[解析] 根据货币数量论的交易方程式MV=PY，GDP=PY，从而GDP=MV，V=GDP/M=3万亿美元/0.5万亿美元=6.0。