Which of the following correctly describes a currency board exchange rate system?
a. The country makes an explicit legislative commitment to exchange domestic currency for a given foreign currency at a fixed exchange rate, combined with restrictions on the issuing authority to ensure fulfillment of its legal obligation
b. the country belongs to a monetary or currency union in which the same legal tender is shared by all members of the union
c. the currency of another country circulates as the sole legal tender
d. the country pegs its currency at a fixed rate to a major currency where the exchange rate fluctuates within a narrow margin of less than 1%