Which of the following statements regarding financing bond purchases with margin accounts is FALSE（）

A. The required margin percentage changes daily.

B. Individuals are more likely than institutions to use margin accounts to finance bond purchases.

C. In the U. S. , margin accounts are regulated by the Federal Reserve.

当纳税人的销售额无法准确提供时，税务机关确定的方法有（）。

A.按纳税人当月同类货物的平均销售价格

B.按纳税人最近日期同类货物的平均销售价格

C.按组成计税价格

D.按纳税本年或上年平均销售额