The Price of a Bouquet of Roses in France Is

The price of a bouquet of roses in France is 4 euros.Tom Smith,a frequent international traveler found that a similar bouquet of roses cost only 3 euros in Germany.A benefit of adopting the euro as a common currency is that it

A) makes it easier to compare prices across Europe.
B) makes Europe an optimal currency area.
C) increases the range of investment options open only to institutions.
D) leads to higher prices,which translate into substantial gains for European producers.
E) decreases competition because it has become harder for consumers to shop around.