It is common practice among currency traders worldwide to both price and trade currencies against the U$.$S$.$ dollar. In fact, the Bank of International Settlements $($BIS$)$ statistics for $2019$ indicate that about $q,$ percent of currency trading in the world involves the U$.$S$.$ dollar on one side of the transaction.

A$)88\%$

B$)75\%$

C$)21\%$

D$)45\%$

E$)31\%$