In 1971, How Did the United States Effectively Abolish the Original

In 1971, how did the United States effectively abolish the original Bretton Woods system?

A) By abandoning the floating exchange rate system in favour of a fixed rate of exchange
B) By suspending the convertibility of US dollars to gold
C) By effectively pulling the United States out of the UN Security Council
D) By suspending American payments to the UN
E) By annulling commitments to regulate structural adjustment policies