Clara is vacationing in Austria. Which currency will she use to in which case has the U.S. dollar weakened?
A. The exchange rate between the U.S. dollar and the yen changes from 1:95 to 1:100.
B. The exchange rate between the U.S. dollar and the euro changes from 1:95 to 1:90.
C. The exchange rate between the U.S. dollar and the euro remains 1:95. for breakfast in her hotel's restaurant?