Under the Bretton Woods system

Question $21$ options:

a$)$

each country established a par value for its currency in relation to the dollar.

b$)$

the U$.$S$.$ dollar was pegged to gold at $$35$ per ounce.

c$)$

each country was responsible for maintaining its exchange rate within $1$ percent of the adopted par value by buying or selling foreign exchanges as necessary.

d$)$

all of the options