Which of the Following Statement Is Correct

Which of the following statement is correct?

A) Since 1974, the major industrial countries have operated under a system of fixed exchange rates based on the gold standard.
B) Many developing nations with low inflation rates have pegged their currencies to the U.S. dollar as a way of allowing modest increases in domestic inflation rates.
C) Large industrial nations with diversified economies and small trade sectors have generally pegged their currencies to one of the world's key currencies.
D) Today, fixed exchange rates are used primarily by small, developing countries that tie their currencies to a key currency such as the U.S. dollar.