Which of the Following Is a Reason Why Nations Began

Which of the following is a reason why nations began abandoning the gold standard in the 1930s?

A) World supply of gold dropped drastically in the 1930s, severely limiting a country's ability to increase its money supply.
B) Imbalances in a country's balance of payments can be corrected only through changes in the entire economy.
C) In order to correct imbalances in its balance of payments, a country was forced on its trading partners to intervene in currency markets.
D) Some nations started hoarding gold in order to manipulate relative exchange rates.