U.S. banks will generally opt to hold excess reserves if they believe general business conditions in the U.S. economy are subject to greater uncertainty. If all else is held constant, what is the most likely impact of this action（）

A. The money supply will decrease.

B. The money supply will increase during a period of inflation, but will decrease if the economy goes into a recession.

C. There will be no effect on the money supply.

华尔兹舞至今仍然保持着“舞蹈之王”的美称，它的基本舞步是（）

A.一拍跳一步

B.二拍跳一步

C.三拍跳一步

D.四拍跳一步