Under a system of floating exchange rates, which of the following would tend to cause an increase in the value of a Country A's currency?
A. Political instability perceived as increasing the risk of foreign investment in Country A.
B. Central bank intervention to increase the demand for the Country A's currency.
C. The perception that Country A's economy is sliding toward recession in the near future.
D. Country A's central bank expanding the money supply to bring about lower interest rates.