Which of the following statements is not true in the current exchange$-$rate system?

Multiple Choice

Major currencies like the U$.$S$.$ dollar, euro, pound, and yen operate mostly in a flexible system responding to supply and demand forces.

Some developing nations peg their currencies to the dollar and allow their currencies to fluctuate with it relative to other currencies.

$$ Each country uses its own unique currency, for example, only the U$.$S$.$ uses the U$.$S$.$ dollar as its currency.