A Recent Study by Andrew Rose of the University of California

A recent study by Andrew Rose of the University of California showed that, on average, two countries that are members of the same currency union

A) trade three times as much with each other as countries that do not share a currency.
B) trade twenty times as much with each other as countries that do not share a currency.
C) trade ten times as much with each other as countries that do not share a currency.
D) trade six times as much with each other as countries that do not share a currency.
E) trade twice as much with each other as countries that do not share a currency.