Though there are other factors, ______the main factor causing the fluctuation of the rate of exchange between this currency and other currencies.

Though there are other factors, ______the main factor causing the fluctuation of the rate of exchange between this currency and other currencies.

A.the regulation of the government is

B.the par value of the currency is

C.supply and demand is

D.the state of a nation’s trade balance of payments is

正确答案是C