One of the Major Provisions of the Bretton Woods Agreement,which

One of the major provisions of the Bretton Woods Agreement,which eventually contributed to the end of the gold standard was:

A) the provision that allowed the United States to unilaterally change the value of the USD in terms of gold.
B) that silver could be substituted for gold as the reference for the value of currencies.
C) that the IMF could adjust the conversion rate of USD into gold periodically.
D) that USD would be converted into the equivalent amount of gold for an entity that requested it.