Which of the Following Statements About Exchange Rates Is Correct

Which of the following statements about exchange rates is correct?

A) The exchange rate, in most cases, is floating: it is determined by the supply and demand for currency, and it can change dramatically.
B) In some cases the exchange rate is pegged, meaning that it is linked to the amount of gold or silver that the country's central bank has in its vaults.
C) When a country experiences inflation, its currency tends to appreciate.
D) When a country experiences a trade deficit, its currency tends to appreciate to compensate.