Which of the following best describes international currency markets under the present international monetary system?

(A) The international payments system is based on the gold standard, and currencies are required to be convertible into gold at fixed prices.

(B) The international monetary system is a managed float in which central banks affect the supply of and demand for currencies.

(C) The World Bank acts as a clearinghouse for settling balance-of-payments accounts.

(D) Member countries must get permission from the International Monetary Fund before changing the international value of their currency.