USAco, a domestic corporation, sells widgets in the US. USAco has a french subsidiary, FRANco, which sell widgets only in France. FRANco is paid in euros for 90% of its sales, and is paid in British pounds for the remaining 10% of its sales. The functional currency of:

(a) USAco is the dollar and FRANco is the euro

(b) USAco is the euro and FRANco is the dollar

(c) both USAco and FRANco is the dollar

(d) USAco is the dollar and FRANco is a proportionate amount of euros and pounds